A laptop, laptop computer, or notebook computer is a small, portable
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...
(PC) with a screen and
alphanumeric keyboard
The technology of computer keyboards includes many elements. Among the more important of these is the switch technology that they use. Computer alphanumeric keyboards typically have 80 to 110 durable switches, generally one for each key. The ch ...
. Laptops typically have a clam shellform factor with the screen mounted on the inside of the upper lid and the keyboard on the inside of the lower lid, although
2-in-1 PC
A 2-in-1 PC, also known as convertible laptop, 2-in-1 tablet, 2-in-1 laptop, 2-in-1 detachable, laplet, tabtop, laptop tablet, or simply 2-in-1, is a portable computer that has features of both tablets and laptops.
Before the emergence of ''2- ...
s with a detachable
keyboard
Keyboard may refer to:
Text input
* Keyboard, part of a typewriter
* Computer keyboard
** Keyboard layout, the software control of computer keyboards and their mapping
** Keyboard technology, computer keyboard hardware and firmware
Music
* Musi ...
are often marketed as laptops or as having a "laptop mode". Laptops are folded shut for transportation, and thus are suitable for mobile use. They are so named because they can be practically placed on a person's
lap
A lap is a surface (usually horizontal) created between the knee and hips of a biped when it is in a seated or lying down position. The lap of a parent or loved one is seen as a physically and psychologically comfortable place for a child to ...
when being used. Today, laptops are used in a variety of settings, such as at work, in education, for
playing games
"Playing Games" is a song by American singer Summer Walker from their debut studio album, '' Over It'' (2019). The song was released as the lead single from the album on August 23, 2019. The extended version features guest vocals from American s ...
,
web browsing
Web navigation refers to the process of navigating a Computer network, network of web resource, information resources in the International World Wide Web Conference, World Wide Web, which is organized as hypertext or hypermedia. The user interface ...
, for personal
multimedia
Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradition ...
, and for general home computer use.
As of 2022, in
American English
American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lan ...
, the terms ''laptop computer'' and ''notebook computer'' are used interchangeably; in other dialects of English, one or the other may be preferred. Although the terms ''notebook computers'' or ''notebooks'' originally referred to a specific size of laptop (originally smaller and lighter than mainstream laptops of the time), the terms have come to mean the same thing and ''notebook'' no longer refers to any specific size.
Laptops combine many of the
input/output
In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...
components and capabilities of a
desktop computer
A desktop computer (often abbreviated desktop) is a personal computer designed for regular use at a single location on or near a desk due to its size and power requirements. The most common configuration has a case that houses the power supply ...
, including the display screen, small speakers, a keyboard,
data storage
Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are conside ...
device, pointing devices (such as a
touch pad
A touchpad or trackpad is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on the operating system that is made output to the screen. Touchp ...
or
pointing stick
A pointing stick (or trackpoint, also referred to generically as a nub or nipple) is a small analog stick used as a pointing device typically mounted centrally in a computer keyboard. Like other pointing devices such as mice, touchpads or trac ...
), with an
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
, a
processor
Processor may refer to:
Computing Hardware
* Processor (computing)
**Central processing unit (CPU), the hardware within a computer that executes a program
*** Microprocessor, a central processing unit contained on a single integrated circuit (I ...
memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...
into a single unit. Most modern laptops feature integrated
webcam
A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in videotelephony, livestreaming and social media, and security. Webcams can be built-in computer hardware or peripheral d ...
s and built-in
microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...
s, while many also have
touchscreen
A touchscreen or touch screen is the assembly of both an input ('touch panel') and output ('display') device. The touch panel is normally layered on the top of an electronic visual display of an information processing system. The display is often ...
s. Laptops can be powered either from an internal
battery
Battery most often refers to:
* Electric battery, a device that provides electrical power
* Battery (crime), a crime involving unlawful physical contact
Battery may also refer to:
Energy source
*Automotive battery, a device to provide power t ...
or by an external
power supply
A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a r ...
from an
AC adapter
An AC adapter or AC/DC adapter is a type of external power supply, often enclosed in a case similar to an AC plug. Other common names include wall wart, power brick, wall charger, and power adapter. Adapters for battery-powered equipment may ...
. Hardware specifications, such as the processor speed and memory capacity, significantly vary between different types, models and
price point
Price points are prices at which demand for a given product is supposed to stay relatively high.
Characteristics
Introductory microeconomics depicts a demand curve as downward-sloping to the right and either linear or gently convex to the origi ...
s.
Design elements, form factor and construction can also vary significantly between models depending on the intended use. Examples of specialized models of laptops include rugged notebooks for use in construction or
military applications
Military science is the study of military processes, institutions, and behavior, along with the study of warfare, and the theory and application of organized coercive force. It is mainly focused on theory, method, and practice of producing mil ...
, as well as low production cost laptops such as those from the One Laptop per Child (OLPC) organization, which incorporate features like solar charging and semi-flexible components not found on most laptop computers. Portable computers, which later developed into modern laptops, were originally considered to be a small
niche market
A niche market is the subset of the market on which a specific product is focused. The market niche defines the product features aimed at satisfying specific market needs, as well as the price range, production quality and the demographics that it ...
, mostly for specialized field applications, such as in the military, for accountants, or traveling sales representatives. As portable computers evolved into modern laptops, they became widely used for a variety of purposes.
History
As the personal computer (PC) became feasible in 1971, the idea of a portable personal computer soon followed. A "personal, portable information manipulator" was imagined by Alan Kay at
Xerox PARC
PARC (Palo Alto Research Center; formerly Xerox PARC) is a research and development company in Palo Alto, California. Founded in 1969 by Jacob E. "Jack" Goldman, chief scientist of Xerox Corporation, the company was originally a division of Xero ...
in 1968, and described in his 1972 paper as the "
Dynabook
The KiddiComp concept, envisioned by Alan Kay in 1968 while a PhD candidate, and later developed and described as the Dynabook in his 1972 proposal "A personal computer for children of all ages", outlines the requirements for a conceptual portabl ...
". The IBM Special Computer APL Machine Portable (SCAMP) was demonstrated in 1973. This prototype was based on the
IBM PALM processor
The PALM (Put All Logic in Microcode) is a 16-bit central processing unit (CPU) developed by IBM. It was used in the IBM 5100 Portable Computer, a predecessor of the IBM PC, and the IBM 5110 and IBM 5120 follow-on machines. It is likely PALM ...
. The IBM 5100, the first commercially available portable computer, appeared in September 1975, and was based on the SCAMP prototype.
As 8-bit CPU machines became widely accepted, the number of portables increased rapidly. The first "laptop-sized notebook computer" was the
Epson HX-20
The Epson HX-20 (also known as the HC-20) was the first "true" laptop computer.Michael R. Peres''The Focal Encyclopedia of Photography'', page 306 Taylor & Francis It was invented in July 1980 by Yukio Yokozawa, who worked for Suwa Seikosha, a bra ...
, invented (patented) by
Suwa Seikosha
was a branch of the Japanese company Seiko that produced clocks, watches, shutters, computer printers and other devices. It was the root of the manufacturing companies of the Seiko Group.
History
*1881 — Kintarō Hattori opens the watc ...
's Yukio Yokozawa in July 1980, introduced at the COMDEX computer show in
Las Vegas
Las Vegas (; Spanish for "The Meadows"), often known simply as Vegas, is the 25th-most populous city in the United States, the most populous city in the state of Nevada, and the county seat of Clark County. The city anchors the Las Vegas ...
Taylor & Francis
Taylor & Francis Group is an international company originating in England that publishes books and academic journals. Its parts include Taylor & Francis, Routledge, F1000 (publisher), F1000 Research or Dovepress. It is a division of Informa ...
It had an
LCD
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but in ...
screen, a rechargeable battery, and a calculator-size printer, in a chassis, the size of an A4
notebook
A notebook (also known as a notepad, writing pad, drawing pad, or legal pad) is a book or stack of paper pages that are often ruled and used for purposes such as note-taking, journaling or other writing, drawing, or scrapbooking.
History
...
. It was described as a "laptop" and "notebook" computer in its patent.
The portable micro computer
Portal
Portal often refers to:
* Portal (architecture), an opening in a wall of a building, gate or fortification, or the extremities (ends) of a tunnel
Portal may also refer to:
Arts and entertainment Gaming
* ''Portal'' (series), two video games ...
of the French company R2E Micral CCMC officially appeared in September 1980 at the Sicob show in Paris. It was a portable microcomputer designed and marketed by the studies and developments department of R2E Micral at the request of the company CCMC specializing in payroll and accounting. It was based on an Intel 8085 processor, 8-bit, clocked at . It was equipped with a central 64 KB RAM, a keyboard with 58 alphanumeric keys and 11 numeric keys (separate blocks), a 32-character screen, a floppy disk: capacity = 140,000 characters, of a thermal printer: speed = 28 characters / second, an asynchronous channel, asynchronous channel, a 220 V power supply. It weighed and its dimensions were 454515cm. It provided total mobility. Its operating system was aptly named Prologue.
The Osborne 1, released in 1981, was a luggable computer that used the
Zilog
Zilog, Inc. is an American manufacturer of microprocessors and 8-bit and 16-bit microcontrollers. It is also a supplier of application-specific embedded system-on-chip (SoC) products.
Its most famous product is the Z80 series of 8-bit microp ...
Z80
The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples were ...
CPU and weighed . It had no battery, a
cathode-ray tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms (oscilloscope), pictur ...
(CRT) screen, and dual single-density floppy drives. Both Tandy/RadioShack and
Hewlett-Packard
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...
(HP) also produced portable computers of varying designs during this period. The first laptops using the flip form factor appeared in the early 1980s. The Dulmont Magnum was released in Australia in 1981–82, but was not marketed internationally until 1984–85. The GRiD Compass 1101, released in 1982, was used at
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
and by the
military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...
, among others. The
Sharp PC-5000
The Sharp PC-5000 was a pioneering laptop computer, announced by Sharp Corporation of Japan in November 1983. It employed a clamshell design in which the display closes over the keyboard, like the earlier GRiD Compass and contemporary Gavilan SC ...
, AmpereBob Armstrong, http://cosy.com/language/cosyhard/cosyhard.htm and Gavilan SC released in 1983. The Gavilan SC was described as a "laptop" by its manufacturer, while the Ampere had a modern clamshell design. The Toshiba T1100 won acceptance not only among PC experts but the mass market as a way to have PC portability.
From 1983 onward, several new input techniques were developed and included in laptops, including the
touch pad
A touchpad or trackpad is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on the operating system that is made output to the screen. Touchp ...
pointing stick
A pointing stick (or trackpoint, also referred to generically as a nub or nipple) is a small analog stick used as a pointing device typically mounted centrally in a computer keyboard. Like other pointing devices such as mice, touchpads or trac ...
(IBM ThinkPad 700, 1992), and handwriting recognition (Linus Write-Top, 1987). Some CPUs, such as the 1990 Intel i386SL, were designed to use minimum power to increase battery life of portable computers and were supported by dynamic power management features such as Intel SpeedStep and AMD
PowerNow!
__NOTOC__
AMD PowerNow! is AMD's dynamic frequency scaling and power saving technology for laptop processors. The CPU's clock speed and VCore are automatically decreased when the computer is under low load or idle, to save battery power, reduce ...
in some designs.
Displays reached 640x480 (
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can now ...
) resolution by 1988 (Compaq SLT/286), and color screens started becoming a common upgrade in 1991, with increases in resolution and screen size occurring frequently until the introduction of 17" screen laptops in 2003. Hard drives started to be used in portables, encouraged by the introduction of 3.5" drives in the late 1980s, and became common in laptops starting with the introduction of 2.5" and smaller drives around 1990; capacities have typically lagged behind physically larger desktop drives.
Common resolutions of laptop
webcam
A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in videotelephony, livestreaming and social media, and security. Webcams can be built-in computer hardware or peripheral d ...
s are 720p (HD), and in lower-end laptops 480p. The earliest known laptops with
1080p
1080p (1920×1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen vert ...
(Full HD) webcams like the Samsung 700G7C were released in the early 2010s.
Optical disc drive
In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only r ...
s became common in full-size laptops around 1997; this initially consisted of CD-ROM drives, which were supplanted by CD-R, DVD, and
Blu-ray
The Blu-ray Disc (BD), often known simply as Blu-ray, is a digital optical disc data storage format. It was invented and developed in 2005 and released on June 20, 2006 worldwide. It is designed to supersede the DVD format, and capable of sto ...
drives with writing capability over time. Starting around 2011, the trend shifted against internal optical drives, and as of 2022, they have largely disappeared, but are still readily available as external
peripheral
A peripheral or peripheral device is an auxiliary device used to put information into and get information out of a computer. The term ''peripheral device'' refers to all hardware components that are attached to a computer and are controlled by the ...
s.
Etymology
While the terms ''laptop'' and ''notebook'' are used interchangeably today, there is some question as to the original etymology and specificity of either term. The term ''laptop'' appears to have been coined in the early 1980s to describe a mobile computer which could be used on one's lap and to distinguish these devices from earlier and much heavier portable computers (informally called "luggables"). The term ''notebook'' appears to have gained currency somewhat later as manufacturers started producing even smaller portable devices, further reducing their weight and size and incorporating a display roughly the size of A4 paper; these were marketed as ''notebooks'' to distinguish them from bulkier mainstream or
desktop replacement
A mobile workstation, also known as a desktop replacement computer (DTR) or workstation laptop, is a personal computer that provides the full capabilities of a workstation-class desktop computer while remaining mobile. They are often larger, bulk ...
laptops.
Types of laptops
Since the introduction of portable computers during the late 1970s, their form has changed significantly, spawning a variety of visually and technologically differing subclasses. Except where there is a distinct legal trademark around a term (notably, Ultrabook), there are rarely hard distinctions between these classes and their usage has varied over time and between different sources. Since the late 2010s, the use of more specific terms has become less common, with sizes distinguished largely by the size of the screen.
Smaller and larger laptops
There were in the past a number of marketing categories for smaller and larger laptop computers; these included " subnotebook" models, low cost "
netbook
Netbook was a commonly used term that identified a product class of small and inexpensive laptops which were sold from 2007 to around 2013. These machines were designed primarily as cost-effective tools for consumers to access the Inte ...
s", and " ultra-mobile PCs" where the size class overlapped with devices like
smartphone
A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...
Desktop replacement
A mobile workstation, also known as a desktop replacement computer (DTR) or workstation laptop, is a personal computer that provides the full capabilities of a workstation-class desktop computer while remaining mobile. They are often larger, bulk ...
" laptops for machines notably larger and heavier than typical to operate more powerful
processors
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...
or
graphics hardware
Graphics hardware is computer hardware that generates computer graphics and allows them to be shown on a display, usually using a graphics card (video card) in combination with a device driver to create the images on the screen.
Types
Grap ...
. All of these terms have fallen out of favor as the size of mainstream laptops has gone down and their capabilities have gone up; except for niche models, laptop sizes tend to be distinguished by the size of the screen, and for more powerful models, by any specialized purpose the machine is intended for, such as a "
gaming laptop
A gaming computer or gaming PC is a personal computer specifically designed for playing video games at very high graphic and gameplay configurations. Gaming PCs typically differ from mainstream personal computers by using high- performance vide ...
technological convergence
Technological convergence is the tendency for technologies that were originally unrelated to become more closely integrated and even unified as they develop and advance. For example, watches, telephones, television, computers, and social media p ...
in the portable computer industry spawned a broad range of devices, which combined features of several previously separate device types. The ''hybrids'', ''convertibles'', and ''2-in-1s'' emerged as crossover devices, which share traits of both tablets and laptops. All such devices have a
touchscreen
A touchscreen or touch screen is the assembly of both an input ('touch panel') and output ('display') device. The touch panel is normally layered on the top of an electronic visual display of an information processing system. The display is often ...
display designed to allow users to work in a ''tablet'' mode, using either
multi-touch
In computing, multi-touch is technology that enables a surface (a touchpad or touchscreen) to recognize the presence of more than one somatosensory system, point of contact with the surface at the same time. The origins of multitouch began at CER ...
gestures or a
stylus
A stylus (plural styli or styluses) is a writing utensil or a small tool for some other form of marking or shaping, for example, in pottery. It can also be a computer accessory that is used to assist in navigating or providing more precision w ...
/ digital pen.
Convertibles are devices with the ability to conceal a hardware keyboard. Keyboards on such devices can be flipped, rotated, or slid behind the back of the chassis, thus transforming from a laptop into a tablet. ''Hybrids'' have a keyboard detachment mechanism, and due to this feature, all critical components are situated in the part with the display. ''2-in-1s'' can have a hybrid or a convertible form, often dubbed ''2-in-1 detachable'' and ''2-in-1 convertibles'' respectively, but are distinguished by the ability to run a desktop OS, such as
Windows 10
Windows 10 is a major release of Microsoft's Windows NT operating system. It is the direct successor to Windows 8.1, which was released nearly two years earlier. It was released to manufacturing on July 15, 2015, and later to retail on J ...
. 2-in-1s are often marketed as ''laptop replacement tablets''.
2-in-1s are often very thin, around , and light devices with a long battery life. 2-in-1s are distinguished from mainstream tablets as they feature an
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...
-architecture
CPU
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...
(typically a low- or ultra-low-voltage model), such as the Intel Core i5, run a full-featured desktop OS like
Windows 10
Windows 10 is a major release of Microsoft's Windows NT operating system. It is the direct successor to Windows 8.1, which was released nearly two years earlier. It was released to manufacturing on July 15, 2015, and later to retail on J ...
, and have a number of typical laptop I/O ports, such as
USB 3
USB 3.0, released in November 2008, is the third major version of the Universal Serial Bus (USB) standard for interfacing computers and electronic devices. Among other improvements, USB 3.0 adds the new transfer rate referred to as '' ...
and Mini DisplayPort.
2-in-1s are designed to be used not only as a
media consumption
Media consumption or media diet is the sum of information and entertainment media taken in by an individual or group. It includes activities such as interacting with new media, reading books and magazines, watching television and film, and listeni ...
device but also as valid desktop or laptop replacements, due to their ability to run ''desktop'' applications, such as
Adobe Photoshop
Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc. for Microsoft Windows, Windows and macOS. It was originally created in 1988 by Thomas Knoll, Thomas and John Knoll. Since then, the software has become the indu ...
. It is possible to connect multiple
peripheral
A peripheral or peripheral device is an auxiliary device used to put information into and get information out of a computer. The term ''peripheral device'' refers to all hardware components that are attached to a computer and are controlled by the ...
devices, such as a mouse, keyboard, and several external displays to a modern 2-in-1.
Microsoft Surface
Microsoft Surface is a series of touchscreen-based personal computers, tablets and interactive whiteboards designed and developed by Microsoft, running the Microsoft Windows operating system, apart from the Surface Duo, which runs on Android ...
Pro-series devices and Surface Book are examples of modern 2-in-1 detachable, whereas
Lenovo Yoga
Lenovo Yoga (stylized as Lenovo YOGA or simply YOGΛ) is a line of consumer-oriented laptop computers and tablets designed, developed and marketed by Lenovo, named for their ability to assume multiple form factors due to a hinged screen.
2012
L ...
-series computers are a variant of 2-in-1 convertibles. While the older
Surface RT
The first-generation Surface (launched as Surface with Windows RT, later marketed as Surface RT) is a hybrid tablet computer developed and manufactured by Microsoft. Announced in June 2012, it was released in October 2012, and was the first pers ...
and
Surface 2
Surface 2 is a Surface-series Windows RT hybrid tablet computer created by Microsoft. It was unveiled on September 23, 2013, and released on October 22, 2013 and is the successor to the original Surface. As of January 2015, Microsoft no long ...
have the same chassis design as the Surface Pro, their use of ARM processors and Windows RT do not classify them as 2-in-1s, but as hybrid tablets. Similarly, a number of hybrid laptops run a
mobile operating system
A mobile operating system is an operating system for mobile phones, tablets, smartwatches, smartglasses, or other non-laptop personal mobile computing devices. While computers such as typical laptops are "mobile", the operating systems used on ...
, such as
Android
Android may refer to:
Science and technology
* Android (robot), a humanoid robot or synthetic organism designed to imitate a human
* Android (operating system), Google's mobile operating system
** Bugdroid, a Google mascot sometimes referred to ...
. These include Asus's Transformer Pad devices, examples of hybrids with a detachable keyboard design, which do not fall in the category of 2-in-1s.
Rugged laptop
A rugged laptop is designed to reliably operate in harsh usage conditions such as strong vibrations, extreme temperatures, and wet or dusty environments. Rugged laptops are bulkier, heavier, and much more expensive than regular laptops, and thus are seldom seen in regular consumer use.
Hardware
The basic components of laptops function identically to their desktop counterparts. Traditionally they were miniaturized and adapted to mobile use, The design restrictions on power, size, and cooling of laptops limit the maximum performance of laptop parts compared to that of desktop components, although that difference has increasingly narrowed.
In general, laptop components are not intended to be replaceable or upgradable by the end-user, except for components that can be detached; in the past, batteries and optical drives were commonly exchangeable. This restriction is one of the major differences between laptops and desktop computers, because the large "
tower
A tower is a tall Nonbuilding structure, structure, taller than it is wide, often by a significant factor. Towers are distinguished from guyed mast, masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting ...
" cases used in desktop computers are designed so that new
motherboard
A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expand ...
s,
hard disk
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
s, sound cards, RAM, and other components can be added. Memory and storage can often be upgraded with some disassembly, but with the most compact laptops, there may be no upgradeable components at all.
The following sections summarizes the differences and distinguishing features of laptop components in comparison to desktop personal computer parts.
=
Externally, it can be a ''glossy'' or a ''matte'' (anti-glare) screen.
Sizes
In the past, there was a broader range of marketing terms (both formal and informal) to distinguish between different sizes of laptops. These included
Netbook
Netbook was a commonly used term that identified a product class of small and inexpensive laptops which were sold from 2007 to around 2013. These machines were designed primarily as cost-effective tools for consumers to access the Inte ...
s, subnotebooks, Ultra-mobile PC, and Desktop replacement computers; these are sometimes still used informally, although they are essentially dead in terms of manufacturer marketing.
As of 2021, mainstream consumer laptops tend to come with 11", 13" or 15"-16" screens; 14" models are more popular among business machines. Larger and smaller models are available, but less common – there is no clear dividing line in minimum or maximum size. Machines small enough to be handheld (screens in the 6–8" range) can be marketed either as very small laptops or "handheld PCs," while the distinction between the largest laptops and "All-in-One" desktops is whether they fold for travel.
Resolution
Having a higher resolution display allows more items to fit onscreen at a time, improving the user's ability to multitask, although at the higher resolutions on smaller screens, the resolution may only serve to display sharper graphics and text rather than increasing the usable area. Since the introduction of the MacBook Pro with Retina display in 2012, there has been an increase in the availability of "HiDPI" (or high
Pixel density
Pixels per inch (ppi) and pixels per centimetre (ppcm or pixels/cm) are measurements of the pixel density of an electronic image device, such as a computer monitor or television display, or image digitizing device such as a camera or image scanner. ...
) displays; as of 2022, this is generally considered to be anything higher than 1920 pixels wide. This has increasingly converged around 4K (3840-pixel-wide) resolutions.
External displays can be connected to most laptops, with most models supporting at least one. The use of technology such as USB4 (section Alternate Mode partner specifications), DisplayPort Alt Mode has been utilized to charge a laptop and provide display output over one USB-C Cable.
Refresh rates and 3D
The earliest laptops known to feature a display with doubled 120 Hz of refresh rate and
active shutter 3D system
An active shutter 3D system (a.k.a. alternate frame sequencing, alternate image, AI, alternating field, field sequential or eclipse method) is a technique of displaying stereoscopic 3D images. It works by only presenting the image intended for t ...
were released in 2011 by
Dell
Dell is an American based technology company. It develops, sells, repairs, and supports computers and related products and services. Dell is owned by its parent company, Dell Technologies.
Dell sells personal computers (PCs), servers, data ...
(M17x) and
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
(700G7A).
Central processing unit (CPU)
A laptop's
CPU
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...
has advanced power-saving features and produces less heat than one intended purely for desktop use. Mainstream laptop CPUs made after 2018 have at least two processor cores, often four cores, and sometimes more, with 8 cores becoming more common.
For the low price and mainstream performance, there is no longer a significant performance difference between laptop and desktop CPUs, but at the high end, the fastest desktop CPUs still substantially outperform the fastest laptop processors, at the expense of massively higher power consumption and heat generation; the fastest laptop processors top out at 56 watts of heat, while the fastest desktop processors top out at 150 watts (and often need water cooling).
There has been a wide range of CPUs designed for laptops available from both
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
,
AMD
Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufactur ...
, and other manufacturers. On non-
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introd ...
architectures, Motorola and IBM produced the chips for the former
PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...
PowerBook
The PowerBook (known as Macintosh PowerBook before 1997) is a family of Macintosh laptop computers designed, manufactured and sold by Apple Computer from 1991 to 2006. During its lifetime, the PowerBook went through several major revisions and r ...
). Between around 2000 to 2014, most full-size laptops had socketed, replaceable CPUs; on thinner models, the CPU was soldered on the motherboard and was not replaceable or upgradable without replacing the motherboard. Since 2015, Intel has not offered new laptop CPU models with pins to be interchangeable, preferring ball grid array chip packages which have to be soldered; and as of 2021, only a few rare models using desktop parts.
In the past, some laptops have used a desktop processor instead of the laptop version and have had high-performance gains at the cost of greater weight, heat, and limited battery life; this is not unknown as of 2022, but since around 2010, the practice has been restricted to small-volume gaming models. Laptop CPUs are rarely able to be overclocked; most use locked processors. Even on gaming models where unlocked processors are available, the cooling system in most laptops is often very close to its limits and there is rarely headroom for an overclocking–related operating temperature increase.
Graphical processing unit
On most laptops, a graphical processing unit (GPU) is ''integrated'' into the CPU to conserve power and space. This was introduced by Intel with the Core i-series of mobile processors in 2010, and similar accelerated processing unit (APU) processors by AMD later that year.
Before that, lower-end machines tended to use graphics processors integrated into the system chipset, while higher-end machines had a separate graphics processor. In the past, laptops ''lacking'' a ''separate'' graphics processor were limited in their utility for gaming and professional applications involving 3D graphics, but the capabilities of CPU-integrated graphics have converged with the low-end of dedicated graphics processors since the mid-2010s.
Higher-end laptops intended for gaming or professional 3D work still come with dedicated and in some cases even dual, graphics processors on the motherboard or as an internal expansion card. Since 2011, these almost always involve switchable graphics so that when there is ''no'' demand for the higher performance dedicated graphics processor, the more power-efficient ''integrated'' graphics processor will be used. Nvidia Optimus and AMD Hybrid Graphics are examples of this sort of system of switchable graphics.
Memory
Since around the year 2000, most laptops have used SO-DIMMRAM, although, as of 2021, an increasing number of models use memory soldered to the motherboard. Before 2000, most laptops used proprietary memory modules if their memory was upgradable.
In the early 2010s, high end laptops such as the 2011 Samsung ''700G7A'' have passed the 10 GB RAM barrier, featuring 16 GB of RAM.
When upgradeable, memory slots are sometimes accessible from the bottom of the laptop for ease of upgrading; in other cases, accessing them requires significant disassembly. Most laptops have two memory slots, although some will have only one, either for cost savings or because some amount of memory is soldered. Some high-end models have four slots; these are usually mobile engineering workstations, although a few high-end models intended for gaming do as well.
As of 2021, 8 GB RAM is most common, with lower-end models occasionally having 4GB. Higher-end laptops may come with 16 GB of RAM or more.
Internal storage
The earliest laptops most often used
floppy disk
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...
for storage, although a few used either RAM disk or tape, by the late 1980s
hard disk drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
s had become the standard form of storage.
Between 1990 and 2009, almost all laptops typically had a
hard disk drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
(HDD) for storage; since then,
solid-state drive
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is ...
s (SSD) have gradually come to supplant hard drives in all but some inexpensive consumer models. Solid-state drives are faster and more power-efficient, as well as eliminating the hazard of drive and data corruption caused by a laptop's physical impacts, as they use no mechanical parts such as a rotational platter. In many cases, they are more compact as well. Initially, in the late 2000s, SSDs were substantially more expensive than HDDs, but as of 2021 prices on smaller capacity (under 1
terabyte
The byte is a units of information, unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character (computing), character of text in a computer and for this ...
) drives have converged; larger capacity drives remain more expensive than comparable-sized HDDs.
Since around 1990, where a hard drive is present it will typically be a 2.5-inch drive; some very compact laptops support even smaller 1.8-inch HDDs, and a very small number used 1"
Microdrive
The Microdrive is a registered trademark for miniature, 1-inch hard disks produced by IBM and Hitachi. These rotational media storage devices were designed to fit in CompactFlash (CF) Type II slots. The release of similar drives by other ...
s. Some SSDs are built to match the size/shape of a laptop hard drive, but increasingly they have been replaced with smaller
mSATA
SATA (Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard t ...
or M.2 cards. SSDs using the newer and much faster
NVM Express
NVM Express (NVMe) or Non-Volatile Memory Host Controller Interface Specification (NVMHCIS) is an open, logical-device interface specification for accessing a computer's non-volatile storage media usually attached via PCI Express (PCIe) bus. The ...
standard for connecting are only available as cards.
As of 2022, many laptops no longer contain space for a 2.5" drive, accepting only M.2 cards; a few of the smallest have storage soldered to the motherboard. For those that can, they can typically contain a single 2.5-inch drive, but a small number of laptops with a screen wider than 15 inches can house two drives.
A variety of external HDDs or
NAS
Nas (born 1973) is the stage name of American rapper Nasir Jones.
Nas, NaS, or NAS may also refer to:
Aviation
* Nasair, a low-cost airline carrier and subsidiary based in Eritrea
* National Air Services, an airline in Saudi Arabia
** Nas Air ( ...
data storage servers with support of RAID technology can be attached to virtually any laptop over such interfaces as
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...
,
FireWire
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony an ...
, eSATA, or Thunderbolt, or over a wired or wireless network to further increase space for the storage of data. Many laptops also incorporate a SD or
microSD
Secure Digital, officially abbreviated as SD, is a proprietary non-volatile flash memory card format developed by the SD Association (SDA) for use in portable devices.
The standard was introduced in August 1999 by joint efforts between SanDis ...
card slot. This enables users to download digital pictures from an SD card onto a laptop, thus enabling them to delete the SD card's contents to free up space for taking new pictures.
Removable media drive
Optical disc drive
In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only r ...
s capable of playing
CD-ROM
A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both comput ...
Blu-ray discs
The Blu-ray Disc (BD), often known simply as Blu-ray, is a digital optical disc data storage format. It was invented and developed in 2005 and released on June 20, 2006 worldwide. It is designed to supersede the DVD format, and capable of sto ...
(BD), were nearly universal on full-sized models between the mid-1990s and the early 2010s. As of 2021, drives are uncommon in compact or premium laptops; they remain available in some bulkier models, but the trend towards thinner and lighter machines is gradually eliminating these drives and players – when needed they can be connected via USB instead.
Inputs
An alphanumeric keyboard is used to enter text, data, and other commands (e.g., function keys). A touchpad (also called a trackpad), a
pointing stick
A pointing stick (or trackpoint, also referred to generically as a nub or nipple) is a small analog stick used as a pointing device typically mounted centrally in a computer keyboard. Like other pointing devices such as mice, touchpads or trac ...
, or both, are used to control the position of the cursor on the screen, and an integrated keyboard is used for typing. Some touchpads have buttons separate from the touch surface, while others share the surface. A quick double-tap is typically registered as a click, and operating systems may recognize multi-finger touch gestures.
An external keyboard and mouse may be connected using a
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...
port or wirelessly, via
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
or similar technology. Some laptops have multitouch
touchscreen
A touchscreen or touch screen is the assembly of both an input ('touch panel') and output ('display') device. The touch panel is normally layered on the top of an electronic visual display of an information processing system. The display is often ...
displays, either available as an option or standard. Most laptops have
webcam
A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in videotelephony, livestreaming and social media, and security. Webcams can be built-in computer hardware or peripheral d ...
s and
microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...
s, which can be used to communicate with other people with both moving images and sound, via
web conferencing
Web conferencing is used as an umbrella term for various types of online conferencing and collaborative services including webinars (web seminars), webcasts, and web meetings. Sometimes it may be used also in the more narrow sense of the peer-le ...
or video-calling software.
Laptops typically have USB ports and a combined headphone/microphone jack, for use with headphones, a combined headset, or an external mic. Many laptops have a card reader for reading digital camera SD cards.
Input/output (I/O) ports
On a typical laptop there are several
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...
ports; if they use only the older USB connectors instead of USB-C, they will typically have an external monitor port (
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can now ...
,
DVI
Digital Visual Interface (DVI) is a video display interface developed by the Digital Display Working Group (DDWG). The digital interface is used to connect a video source, such as a video display controller, to a display device, such as a comp ...
,
HDMI
High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, ...
or Mini DisplayPort or occasionally more than one), an audio in/out port (often in form of a single socket) is common. It is possible to connect up to three external displays to a 2014-era laptop via a single Mini DisplayPort, using
multi-stream transport
DisplayPort (DP) is a digital display interface developed by a consortium of PC and chip manufacturers and standardized by the Video Electronics Standards Association (VESA). It is primarily used to connect a video source to a display device s ...
technology.
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
, in a 2015 version of its MacBook, transitioned from a number of different I/O ports to a single
USB-C
USB-C (properly known as USB Type-C) is a 24-pin USB connector system with a rotationally symmetrical connector. The designation C refers only to the connector's physical configuration or form factor and should not be confused with the conne ...
port. This port can be used both for charging and connecting a variety of devices through the use of aftermarket adapters. Apple has since transitioned back to using a number of different ports. Google, with its updated version of
Chromebook Pixel
The Chromebook Pixel is a 2013 laptop at the high end of Google's Chromebook family of machines, which all come preinstalled with ChromeOS operating system.
, shows a similar transition trend towards USB-C, although keeping older USB Type-A ports for a better compatibility with older devices. Although being common until the end of the 2000s decade,
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
network port are rarely found on modern laptops, due to widespread use of
wireless network
A wireless network is a computer network that uses wireless data connections between network nodes.
Wireless networking is a method by which homes, telecommunications networks and business installations avoid the costly process of introducing c ...
ing, such as
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
.
Legacy port
In computing, a legacy port is a computer port or connector that is considered by some to be fully or partially superseded. The replacement ports usually provide most of the functionality of the legacy ports with higher speeds, more compact desi ...
s such as a
PS/2
The Personal System/2 or PS/2 is IBM's second generation of personal computers. Released in 1987, it officially replaced the IBM PC, XT, AT, and PC Convertible in IBM's lineup. Many of the PS/2's innovations, such as the 16550 UART (serial po ...
parallel port
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once ( parallel ...
, or
FireWire
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony an ...
are provided on some models, but they are increasingly rare. On
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
's systems, and on a handful of other laptops, there are also Thunderbolt ports, but Thunderbolt 3 uses USB-C. Laptops typically have a headphone jack, so that the user can connect headphones or amplified speaker systems for listening to music or other audio.
Expansion cards
In the past, a
PC Card
In computing, PC Card is a configuration for computer parallel communication peripheral interface, designed for laptop computers. Originally introduced as PCMCIA, the PC Card standard as well as its successors like CardBus were defined and devel ...
(formerly
PCMCIA
The Personal Computer Memory Card International Association (PCMCIA) was a group of computer hardware manufacturers, operating under that name from 1989 to 2009. Starting with the PCMCIA card in 1990 (the name later simplified to ''PC Card''), i ...
) or ExpressCard slot for expansion was often present on laptops to allow adding and removing functionality, even when the laptop is powered on; these are becoming increasingly rare since the introduction of USB 3.0. Some internal subsystems such as Ethernet, Wi-Fi, or a wireless cellular modem can be implemented as replaceable internal expansion cards, usually accessible under an access cover on the bottom of the laptop. The standard for such cards is
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common ...
, which comes in both
mini
The Mini is a small, two-door, four-seat car, developed as ADO15, and produced by the British Motor Corporation (BMC) and its successors, from 1959 through 2000. Minus a brief hiatus, original Minis were built for four decades and sold during ...
and even smaller M.2 sizes. In newer laptops, it is not uncommon to also see
Micro SATA
SATA (Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard to ...
(mSATA) functionality on PCI Express Mini or M.2 card slots allowing the use of those slots for SATA-based solid-state drives.
Battery and power supply
Since the late 1990s, laptops have typically used
lithium ion
A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also se ...
or
lithium polymer
A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly, lithium-poly and others), is a rechargeable battery of lithium-ion technology using a polymer electrolyte instead of a liquid electrolyt ...
batteries
Battery most often refers to:
* Electric battery, a device that provides electrical power
* Battery (crime), a crime involving unlawful physical contact
Battery may also refer to:
Energy source
*Automotive battery, a device to provide power t ...
, These replaced the older
nickel metal-hydride
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
typically used in the 1990s, and nickel–cadmium batteries used in most of the earliest laptops. A few of the oldest laptops used non-rechargeable batteries, or lead–acid batteries.
Battery life is highly variable by model and workload and can range from one hour to nearly a day. A battery's performance gradually decreases over time; a noticeable reduction in capacity is typically evident after two to three years of regular use, depending on the charging and discharging pattern and the design of the battery. Innovations in laptops and batteries have seen situations in which the battery can provide up to 24 hours of continued operation, assuming average power consumption levels. An example is the HP EliteBook 6930p when used with its ultra-capacity battery.
Laptops with removable batteries may support larger replacement batteries with extended capacity.
A laptop's battery is charged using an external
power supply
A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a r ...
, which is plugged into a wall outlet. The power supply outputs a DC voltage typically in the range of 7.2—24 volts. The power supply is usually external and connected to the laptop through a DC connector cable. In most cases, it can charge the battery and power the laptop simultaneously. When the battery is fully charged, the laptop continues to run on power supplied by the external power supply, avoiding battery use. If the used power supply is not strong enough to power computing components and charge the battery simultaneously, the battery may charge in a shorter period of time if the laptop is turned off or sleeping. The charger typically adds about to the overall transporting weight of a laptop, although some models are substantially heavier or lighter. Most 2016-era laptops use a
smart battery
A smart battery or a smart battery pack is a rechargeable battery pack with a built-in battery management system (BMS), usually designed for use in a portable computer such as a laptop. In addition to the usual positive and negative terminals, ...
, a rechargeable battery pack with a built-in battery management system (BMS). The smart battery can internally measure voltage and current, and deduce charge level and State of Health (SoH) parameters, indicating the state of the cells.
Power connectors
Historically,
DC connectors
A DC connector (or DC plug, for one common type of connector) is an electrical connector for supplying direct current (DC) power.
Compared to domestic AC power plugs and sockets, DC connectors have many more standard types that are not intercha ...
, typically cylindrical/barrel-shaped coaxial power connectors have been used in laptops. Some vendors such as
Lenovo
Lenovo Group Limited, often shortened to Lenovo ( , ), is a Chinese Multinational corporation, multinational technology company specializing in designing, manufacturing, and marketing consumer electronics, Personal computer, personal computers, ...
made intermittent use of a rectangular connector.
Some connector heads feature a center pin to allow the end device to determine the power supply type by measuring the resistance between it and the connector's negative pole (outer surface). Vendors may block charging if a power supply is not recognized as original part, which could deny the legitimate use of universal third-party chargers.
With the advent of
USB-C
USB-C (properly known as USB Type-C) is a 24-pin USB connector system with a rotationally symmetrical connector. The designation C refers only to the connector's physical configuration or form factor and should not be confused with the conne ...
power delivery
Electricity delivery is the process that starts after generation of electricity in the power station, up to the use by the consumer.
The main processes in electricity delivery are, by order:
* Transmission
* Distribution
* Retailing
See also
*Ele ...
and data transfer. Its support for 20 V (common laptop power supply voltage) and 5 A typically suffices for low to mid-end laptops, but some with higher power demands such as
gaming laptop
A gaming computer or gaming PC is a personal computer specifically designed for playing video games at very high graphic and gameplay configurations. Gaming PCs typically differ from mainstream personal computers by using high- performance vide ...
s depend on dedicated DC connectors to handle currents beyond 5 A without risking overheating, some even above 10 A. Additionally, dedicated DC connectors are more durable and less prone to wear and tear from frequent reconnection, as their design is less delicate.
Cooling
Waste heat
Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...
from the operation is difficult to remove in the compact internal space of a laptop. The earliest laptops used passive cooling; this gave way to
heat sink
A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, th ...
s placed directly on the components to be cooled, but when these hot components are deep inside the device, a large space-wasting air duct is needed to exhaust the heat. Modern laptops instead rely on heat pipes to rapidly move waste heat towards the edges of the device, to allow for a much smaller and compact fan and heat sink cooling system. Waste heat is usually exhausted away from the device operator towards the rear or sides of the device. Multiple air intake paths are used since some intakes can be blocked, such as when the device is placed on a soft conforming surface like a chair cushion. Secondary device temperature monitoring may reduce performance or trigger an emergency shutdown if it is unable to dissipate heat, such as if the laptop were to be left running and placed inside a carrying case. Aftermarket cooling pads with external fans can be used with laptops to reduce operating temperatures.
Docking station
A
docking station
In computing, a docking station or port replicator (hub) or dock provides a simplified way to ''plug-in'' a mobile device, such as a laptop, to common peripherals. Because a wide range of dockable devices—from mobile phones to wireless mouse ...
(sometimes referred to simply as a ''dock'') is a laptop accessory that contains multiple ports and in some cases expansion slots or bays for fixed or removable drives. A laptop connects and disconnects to a docking station, typically through a single large proprietary connector. A docking station is an especially popular laptop accessory in a corporate computing environment, due to a possibility of a docking station transforming a laptop into a full-featured desktop replacement, yet allowing for its easy release. This ability can be advantageous to " road warrior" employees who have to travel frequently for work, and yet who also come into the office. If more ports are needed, or their position on a laptop is inconvenient, one can use a cheaper passive device known as a
port replicator
In computing, a docking station or port replicator (hub) or dock provides a simplified way to ''plug-in'' a mobile device, such as a laptop, to common peripherals. Because a wide range of dockable devices—from mobile phones to wireless mouse ...
. These devices mate to the connectors on the laptop, such as through
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...
or
FireWire
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony an ...
.
Charging trolleys
Laptop charging trolley
Laptop charging trolleys, also known as laptop trolleys or laptop carts, are mobile storage containers to charge laptops, netbooks and tablet computers en masse. The trolleys are predominantly used in schools that have replaced their traditional ...
s, also known as laptop trolleys or laptop carts, are mobile storage containers to charge multiple laptops,
netbooks
Netbook was a commonly used term that identified a product class of small and inexpensive laptops which were sold from 2007 to around 2013. These machines were designed primarily as cost-effective tools for consumers to access the Inte ...
, and
tablet computer
A tablet computer, commonly shortened to tablet, is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package. Tablets, being comput ...
s at the same time. The trolleys are used in schools that have replaced their traditional static computer labs suites of desktop equipped with "tower" computers, but do not have enough plug sockets in an individual classroom to charge all of the devices. The trolleys can be wheeled between rooms and
classrooms
A classroom or schoolroom is a learning space in which both children and adults learn. Classrooms are found in educational institutions of all kinds, ranging from preschools to universities, and may also be found in other places where education ...
so that all students and teachers in a particular building can access fully chargedIT equipment.
Laptop charging trolleys are also used to deter and protect against opportunistic and organized theft. Schools, especially those with open plan designs, are often prime targets for
thieves
Theft is the act of taking another person's property or services without that person's permission or consent with the intent to deprive the rightful owner of it. The word ''theft'' is also used as a synonym or informal shorthand term for some ...
who steal high-value items. Laptops, netbooks, and tablets are among the highest–value portable items in a school. Moreover, laptops can easily be concealed under clothing and stolen from buildings. Many types of laptop–charging trolleys are designed and constructed to protect against theft. They are generally made out of steel, and the laptops remain locked up while not in use. Although the trolleys can be moved between areas from one classroom to another, they can often be mounted or locked to the floor, support pillars, or walls to prevent thieves from stealing the laptops, especially overnight.
Solar panels
In some laptops, solar panels are able to generate enough solar power for the laptop to operate. The One Laptop Per Child Initiative released the OLPC XO-1 laptop which was tested and successfully operated by use of solar panels. Presently, they are designing an
OLPC XO-3
XO-3 was a design for a tablet/e-book reader intended to be developed under the One Laptop per Child (OLPC) initiative, but the project was cancelled in November 2012, replaced by the XO tablet.
History
It was planned to have a tablet compute ...
laptop with these features. The OLPC XO-3 can operate with 2 watts of electricity because its renewable energy resources generate a total of 4 watts.
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
has also designed the NC215S solar–powered notebook that will be sold commercially in the U.S. market.
Accessories
A common accessory for laptops is a laptop sleeve, laptop skin, or laptop case, which provides a degree of protection from scratches. Sleeves, which are distinguished by being relatively thin and flexible, are most commonly made of
neoprene
Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene.Werner Obrecht, Jean-Pierre Lambert, Michael Happ, Christiane Oppenheimer-Stix, John Dunn and Ralf Krüger "Rubber, 4. Emulsion R ...
waterproofing
Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environme ...
. Bulkier and sturdier cases can be made of metal with polyurethane padding inside and may have locks for added security. Metal, padded cases also offer protection against impacts and drops. Another common accessory is a
laptop cooler
A laptop/notebook cooler, cooling pad, cooler pad or chill mat is an accessory for laptop computers intended to reduce their operating temperature when the laptop is unable to sufficiently cool itself. Laptop coolers are intended to protect bot ...
, a device that helps lower the internal temperature of the laptop either actively or passively. A common active method involves using electric fans to draw heat away from the laptop, while a passive method might involve propping the laptop up on some type of pad so it can receive more airflow. Some stores sell laptop pads that enable a reclining person on a bed to use a laptop.
Modularity
Some of the components of earlier models of laptops can easily be replaced without opening completely its bottom part, such as keyboard, battery, hard disk, memory modules, CPU cooling fan, etc.
Some of the components of recent models of laptops reside inside. Replacing most of its components, such as keyboard, battery, hard disk, memory modules, CPU cooling fan, etc., requires removal of its either top or bottom part, removal of the motherboard, and returning them.
In some types, solder and glue are used to mount components such as RAM, storage, and batteries, making repairs additionally difficult.
Obsolete features
Features that certain early models of laptops used to have that are not available in most current laptops include:
* Reset ("cold restart") button in a hole (needed a thin metal tool to press)
* Instant power off button in a hole (needed a thin metal tool to press)
* Integrated charger or power adapter inside the laptop
* Dedicated Media buttons (Internet, Volume, Play, Pause, Next, Previous)
* Floppy disk drive
* Serial port
*
Parallel port
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once ( parallel ...
*
Modem
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...
Docking port
A dock connector is a connector used to attach a mobile electronic device simultaneously to multiple external resources. The dock connector will typically carry a variety of signals and power, through a single connector, to simplify the process o ...
* Shared
PS/2
The Personal System/2 or PS/2 is IBM's second generation of personal computers. Released in 1987, it officially replaced the IBM PC, XT, AT, and PC Convertible in IBM's lineup. Many of the PS/2's innovations, such as the 16550 UART (serial po ...
input device port
*
IrDA
The Infrared Data Association (IrDA) is an industry-driven interest group that was founded in 1994 by around 50 companies. IrDA provides specifications for a complete set of protocols for wireless infrared communications, and the name "IrDA" also ...
*
S-video
S-Video (also known as separate video, Y/C, and erroneously Super-Video ) is an analog video signal format that carries standard-definition video, typically at 525 lines or 625 lines. It encodes video luma and chrominance on two separate channe ...
PC Card
In computing, PC Card is a configuration for computer parallel communication peripheral interface, designed for laptop computers. Originally introduced as PCMCIA, the PC Card standard as well as its successors like CardBus were defined and devel ...
/
PCMCIA
The Personal Computer Memory Card International Association (PCMCIA) was a group of computer hardware manufacturers, operating under that name from 1989 to 2009. Starting with the PCMCIA card in 1990 (the name later simplified to ''PC Card''), i ...
*Portability is usually the first feature mentioned in any comparison of laptops versus desktop PCs. Physical portability allows a laptop to be used in many places—not only at home and the office but also during commuting and flights, in coffee shops, in lecture halls and libraries, at clients' locations or a meeting room, etc. Within a home, portability enables laptop users to move their devices from room to room. Portability offers several distinct advantages:
* Productivity: Using a laptop in places where a desktop PC cannot be used can help employees and students to increase their productivity on work or school tasks, such as an office worker reading their work e-mails during an hour-long commute by train, or a student doing their homework at the university coffee shop during a break between lectures, for example.
* Up-to-date information: Using a single laptop prevents fragmentation of files across multiple PC's as the files exist in a single location and are always up-to-date.
* Connectivity: A key advantage of laptops is that they almost always have integrated connectivity features such as
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
and
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
, and sometimes connection to cellular networks either through native integration or use of a
hotspot
Hotspot, Hot Spot or Hot spot may refer to:
Places
* Hot Spot, Kentucky, a community in the United States
Arts, entertainment, and media Fictional entities
* Hot Spot (comics), a name for the DC Comics character Isaiah Crockett
* Hot Spot (Tra ...
. Wi-Fi networks and laptop programs are especially widespread at university campuses.
Other advantages of laptops:
* Size: Laptops are smaller than desktop PCs. This is beneficial when space is at a premium, for example in small apartments and student dorms. When not in use, a laptop can be closed and put away in a desk drawer.
* Low power consumption: Laptops are several times more power-efficient than desktops. A typical laptop uses 10–100 W, compared to 200–800W for desktops. This could be particularly beneficial for large businesses, which run hundreds of personal computers thus
economies of scale
In microeconomics, economies of scale are the cost advantages that enterprises obtain due to their scale of operation, and are typically measured by the amount of output produced per unit of time. A decrease in cost per unit of output enables ...
, and homes where there is a computer running 24/7 (such as a home media server, print server, etc.).
* Quiet: Laptops are typically much quieter than desktops, due both to the components (often silent
solid-state drives
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is a ...
replacing hard drives) and to less heat production leading to the use of fewer, sometimes no cooling fans. The latter has given rise to laptops that have no moving parts, resulting in complete silence during use.
* Battery: a charged laptop can continue to be used in case of a power outage and is not affected by short power interruptions and blackouts, an issue that is present with desktop PC's.
* All-in-One: designed to be portable, most modern laptops have all components integrated into the chassis. For desktops (excluding all-in-ones) this is usually divided into the desktop "tower" (the unit with the CPU, hard drive, power supply, etc.), keyboard, mouse, display screen, and optional peripherals such as speakers.
Disadvantages
Compared to desktop PCs, laptops have disadvantages in the following areas:
Performance
The majority of laptops released in 2022 are capable of common tasks such as web browsing, video playback, and office applications, even at the low end. That said, performance of desktops often surpass comparably priced laptops. The upper limits of performance of laptops remain lower than desktops, due to mostly practical reasons, such as decreased battery life, increased size and heat, etc.
Upgradeability
The upgradeability of laptops is very limited compared to thoroughly standardized desktops, due to technical and economic reasons. In general, hard drives and memory can be upgraded easily. Due to the integrated nature of laptops, however, the motherboard, CPU, and graphics, are seldom officially upgradeable. Some efforts towards industry standard parts and layouts have been attempted, such as
Common Building Block
Common Building Block (CBB) was a set of technical standards for laptop components introduced by Intel in 2005, and adopted by some manufacturers, including Asus, Compal, and Quanta.
Creation
In 2004, the Common Building Block program promoted ...
, but the industry remains largely
proprietary
{{Short pages monitor
see also: E-Waste
The list of materials that go into a laptop computer is long, and many of the substances used, such as
beryllium
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form mi ...
,
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
,
chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
, and
mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
compounds, are
toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
or
carcinogenic
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...
to humans. Although these toxins are relatively harmless when the laptop is in use, concerns that discarded laptops cause a serious health and environmental risks when improperly discarded have arisen. The Waste Electrical and Electronic Equipment Directive (WEEE Directive) in Europe specified that all laptop computers must be recycled by law. Similarly, the U.S. Environmental Protection Agency (
EPA
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
) has outlawed
landfill
A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...
dumping or the incinerating of discarded laptop computers.
Most laptop computers begin the recycling process with a method known as
Demanufacturing
Demanufacturing is a process where a product after extensive usage, often at the end of its lifespan, is then disassembled into components, the components are classified as to functionality and components suitable for reuse are again to returned to ...
, this involves the physical separation of the components of the laptop. These components are then either grouped into materials (e.g. plastic, metal and glass) for recycling or more complex items that require more advanced materials separation (e.g.) circuit boards, hard drives and batteries.
Corporate laptop recycling can require an additional process known as data destruction. The data destruction process ensures that all information or data that has been stored on a laptop hard drive can never be retrieved again. Below is an overview of some of the data protection and environmental laws and regulations applicable for laptop recycling data destruction:
*
Data Protection Act 1998
The Data Protection Act 1998 (DPA, c. 29) was an Act of Parliament of the United Kingdom designed to protect personal data stored on Computer, computers or in an organised paper filing system. It enacted provisions from the European Union (EU) Da ...
Financial Conduct Authority
The Financial Conduct Authority (FCA) is a financial regulation, financial regulatory body in the United Kingdom, but operates independently of the UK Government, and is financed by charging fees to members of the financial services industry. The ...
* Sarbanes-Oxley Act
* PCI-DSS Data Security Standard
* Waste, Electronic & Electrical Equipment Directive (
WEEE
The Waste Electrical and Electronic Equipment Directive (WEEE Directive) is the European Community Directive 2012/19/EU on waste electrical and electronic equipment (WEEE) which, together with the RoHS Directive 2011/65/EU, became European La ...
)
* Basel Convention
*
Bank Secrecy Act
The Bank Secrecy Act of 1970 (BSA), also known as the Currency and Foreign Transactions Reporting Act, is a U.S. law requiring financial institutions in the United States to assist U.S. government agencies in detecting and preventing money laund ...
(BSA)
* FACTA Sarbanes-Oxley Act
* FDA Security Regulations (21 C.F.R. part 11)
* Gramm-Leach-Bliley Act (GLBA)
*
HIPAA
The Health Insurance Portability and Accountability Act of 1996 (HIPAA or the Kennedy– Kassebaum Act) is a United States Act of Congress enacted by the 104th United States Congress and signed into law by President Bill Clinton on August 21, 19 ...
(Health Insurance Portability and Accountability Act)
* NIST SP 800–53
* Add NIST SP 800–171
* Identity Theft and Assumption Deterrence Act
* Patriot Act of 2002
* PCI Data Security Standard
* US Safe Harbor Provisions
* Various state laws
* JAN 6/3
* Gramm-leach-Bliley Act
* DCID
Extreme use
The ruggedized
Grid Compass
The Grid Compass (written ''GRiD'' by its manufacturer GRiD Systems Corporation) is one of the first laptop computers.
History
Development began in 1979, and the main buyer was the U.S. government. NASA used it on the Space Shuttle during th ...
computer was used since the early days of the Space Shuttle program. The first commercial laptop used in space was a Macintosh portable in 1990 on Space Shuttle mission STS-41 and again in 1991 aboard
STS-43
STS-43, the ninth mission for Space Shuttle ''Atlantis'', was a nine-day mission whose primary goal was launching the TDRS-E satellite (TDRS-5). The flight also tested an advanced heatpipe radiator for potential use on the then-future space s ...
. Apple and other laptop computers continue to be flown aboard crewed spaceflights, though the only long-duration flight certified computer for the International Space Station is the ThinkPad. As of 2011, over 100 ThinkPads were aboard the ISS. Laptops used aboard the International Space Station and other spaceflights are generally the same ones that can be purchased by the general public but needed modifications are made to allow them to be used safely and effectively in a weightless environment such as updating the cooling systems to function without relying on hot air rising and accommodation for the lower cabin air pressure. Laptops operating in harsh usage environments and conditions, such as strong vibrations, extreme temperatures, and wet or dusty conditions differ from those used in space in that they are custom designed for the task and do not use
commercial off-the-shelf
Commercial off-the-shelf or commercially available off-the-shelf (COTS) products are packaged or canned (ready-made) hardware or software, which are adapted aftermarket to the needs of the purchasing organization, rather than the commissioning of ...
hardware.
See also
*
List of computer size categories
This list of computer size categories attempts to list commonly used categories of computer by the physical size of the device and its chassis or case, in descending order of size. One generation's "supercomputer" is the next generation's "mainfra ...
*
List of laptop brands and manufacturers
This is a list of laptop brands and manufacturers.
Manufacturers Major brands
Other brands
No longer manufacturing computers
Defunct brands
Original design manufacturers (ODMs)
The vast majority of laptops on the market are manufa ...
*
Netbook
Netbook was a commonly used term that identified a product class of small and inexpensive laptops which were sold from 2007 to around 2013. These machines were designed primarily as cost-effective tools for consumers to access the Inte ...
*
Smartbook
A smartbook was a class of mobile device that combined certain features of both a smartphone and netbook computer, produced between 2009 and 2010.
Smartbooks were advertised with features such as always on, all-day battery life, 3G, or Wi-Fi conn ...
Smartphone
A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...
Mobile broadband
Mobile broadband is the marketing term for Wireless broadband, wireless Internet access via mobile networks. Access to the network can be made through a portable modem, wireless modem, or a Tablet computer, tablet/smartphone (possibly Tetherin ...
*
Mobile Internet device
A mobile Internet device (MID) is a multimedia capable mobile device providing wireless Internet access. They are designed to provide entertainment, information and location-based services for personal or business use. They allow 2-way communicati ...
(MID)
*
Personal digital assistant
A personal digital assistant (PDA), also known as a handheld PC, is a variety mobile device which functions as a personal information manager. PDAs have been mostly displaced by the widespread adoption of highly capable smartphones, in partic ...
*
VIA OpenBook
VIA OpenBook is a laptop reference design from VIA Technologies, announced in 2008. The laptop case design was released as open source. Windowsfordevices.com. May 27, 2008.
Specifications
Dimensions
*Dimensions: 24.0w x 17.5d x 3.62h cm (a ...
*
Tethering
Tethering, or phone-as-modem (PAM) is the sharing of a mobile device's Internet connection with other connected computers. Connection of a mobile device with other devices can be done over wireless LAN (Wi-Fi), over Bluetooth or by physical conne ...
*
XJACK
In laptop computing, the XJACK is a type of extendable connector or antenna for a type II PC card, designed by the Megahertz subsidiary of 3Com. When not in use, the XJACK retracts into the PC card for storage.
The XJACK was originally used i ...
*
Open-source computer hardware
Open-source hardware (OSH) consists of physical artifact (software development), artifacts of technology designed and offered by the open-design movement. Both free and open-source software (FOSS) and open-source hardware are created by this ope ...
*
Novena
A novena (from Latin: ''novem'', "nine") is an ancient tradition of devotional praying in Christianity, consisting of private or public prayers repeated for nine successive days or weeks. The nine days between the Feast of the Ascension and Pen ...
Stereoscopy
Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word ''stereoscopy'' derives . Any stereoscopic image is ...