In computer technology and
telecommunications
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that fe ...
, online indicates a state of connectivity and offline indicates a disconnected state. In modern terminology, this usually refers to an
Internet connection
Internet access is the ability of individuals and organizations to connect to the Internet using computer terminals, computers, and other devices; and to access services such as email and the World Wide Web. Internet access is sold by Internet ...
, but (especially when expressed "on line" or "on the line") could refer to any piece of equipment or functional unit that is connected to a larger system. Being online means that the equipment or subsystem is connected, or that it is ready for use.
"Online" has come to describe activities performed on and data available on the Internet,
for example: "
online identity
Internet identity (IID), also online identity or internet persona, is a social identity that an Internet user establishes in online communities and websites. It may also be an actively constructed presentation of oneself. Although some people choo ...
", "
online predator
Online predators are individuals who commit child sexual abuse that begins or takes place on the Internet.
Conceptions
Internet-facilitated crimes against minors involve deceit and begin with adults communicating with children over the Internet ...
", "
online gambling
Online gambling is any kind of gambling conducted on the internet. This includes virtual poker, casinos and sports betting. The first online gambling venue opened to the general public was ticketing for the Liechtenstein International Lottery i ...
", "
online game", "
online shopping
Online shopping is a form of electronic commerce which allows consumers to directly buy goods or services from a seller over the Internet using a web browser or a mobile app. Consumers find a product of interest by visiting the website of the ...
", "
online banking
Online banking, also known as internet banking, web banking or home banking, is an electronic payment system that enables customers of a bank or other financial institution to conduct a range of financial transactions through the financial ins ...
", and "
online learning
Educational technology (commonly abbreviated as edutech, or edtech) is the combined use of computer hardware, software, and educational theory and practice to facilitate learning. When referred to with its abbreviation, edtech, it often refer ...
". Similar meaning is also given by the prefixes "cyber" and "e", as in the words "
cyberspace", "
cybercrime
A cybercrime is a crime that involves a computer or a computer network.Moore, R. (2005) "Cyber crime: Investigating High-Technology Computer Crime," Cleveland, Mississippi: Anderson Publishing. The computer may have been used in committing th ...
", "
email
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...
", and "
ecommerce
E-commerce (electronic commerce) is the activity of electronically buying or selling of products on online services or over the Internet. E-commerce draws on technologies such as mobile commerce, electronic funds transfer, supply chain managemen ...
".
In contrast, "offline" can refer to either computing activities performed while disconnected from the Internet, or alternatives to Internet activities (such as shopping in
brick-and-mortar
Brick and mortar (also bricks and mortar or B&M) refers to a physical presence of an organization or business in a building or other structure. The term ''brick-and-mortar business'' is often used to refer to a company that possesses or leases r ...
stores). The term "offline" is sometimes used interchangeably with the acronym "IRL", meaning "in real life".
History
During the 19th century, the term ''on line'' was commonly used in both the
railroad
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
and
telegraph
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...
industries. For railroads, a
signal box would send messages down the line (track), via a telegraph line (cable), indicating the track's status: ''Train on line'' or ''Line clear''.
Telegraph linemen would refer to sending current through a line as ''direct on line'' or ''battery on line''; or they may refer to a problem with the circuit as being ''on line'', as opposed to the power source or end-point equipment.
Since at least 1950, in
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...
, the terms ''on-line'' and ''off-line'' have been used to refer to whether machines, including
computers and
peripheral devices
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 ...
, are connected or not.
Here is an excerpt from the 1950 book ''High-Speed Computing Devices'':
: The use of automatic computing equipment for large-scale reduction of data will be strikingly successful only if means are provided for the automatic transcription of these data to a form suitable for automatic entry into the machine. For some applications, of which the most prominent are those in which the reduced data are used to control the process being measured, the input must be developed for ''on-line'' operation. In on-line operation the input is communicated directly and without delay to the data-reduction device. For other applications, ''off-line'' operation, involving automatic transcription of data in a form suitable for later introduction to the machine, may be tolerated. These requirements may be compared with
teleprinter
A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Init ...
operating requirements. For example, some teletype machines operate on line. Their operators are in instantaneous communication. Other teletype machines are operated off line, through the intervention of
punched paper tape. The message is preserved by means of holes punched in the tape and is transmitted later by feeding the tape to another machine.
Examples
Offline e-mail
One example of a common use of these concepts with email is a
mail user agent
The mail or post is a system for physically transporting postcards, letters, and parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid-19th century, national postal syst ...
(MUA) that can be instructed to be in either online or offline states. One such MUA is
Microsoft Outlook. When online it will attempt to connect to mail servers (to check for new mail at regular intervals, for example), and when offline it will not attempt to make any such connection. The online or offline state of the MUA does not necessarily reflect the connection status between the computer on which it is running and the internet i.e. the computer itself may be online—connected to Internet via a cable modem or other means—while Outlook is kept offline by the user, so that it makes no attempt to send or to receive messages. Similarly, a computer may be configured to employ a
dial-up connection on demand (as when an application such as Outlook attempts to make connection to a server), but the user may not wish for Outlook to trigger that call whenever it is configured to check for mail.
Offline media playing
Another example of the use of these concepts is
digital audio technology. A tape recorder,
digital audio editor, or other device that is online is one whose clock is under the control of the clock of a synchronization master device. When the sync master commences playback, the online device automatically synchronizes itself to the master and commences playing from the same point in the recording. A device that is offline uses no external clock reference and relies upon its own internal clock. When many devices are connected to a sync master it is often convenient, if one wants to hear just the output of one single device, to take it offline because, if the device is played back online, all synchronized devices have to locate the playback point and wait for each other device to be in synchronization. (For related discussion, see
MIDI timecode
MIDI time code (MTC) embeds the same timing information as standard SMPTE timecode as a series of small 'quarter-frame' MIDI messages. There is no provision for the user bits in the standard MIDI time code messages, and SysEx messages are used t ...
,
word sync
Word sync is a technique for synchronizing digital audio signals between high-end professional devices; such as CD players, audio I/O cards, etc. It allows all the components in the signal path to process the data and remain synchronized with each ...
, and recording system synchronization.)
Offline browsing
A third example of a common use of these concepts is a
web browser
A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on ...
that can be instructed to be in either online or offline states. The browser attempts to fetch pages from servers while only in the online state. In the offline state, or "offline mode", users can perform offline browsing, where pages can be browsed using local copies of those pages that have previously been downloaded while in the online state. This can be useful when the computer is offline and connection to the Internet is impossible or undesirable. The pages are downloaded either implicitly into the web browser's own
cache
Cache, caching, or caché may refer to:
Places United States
* Cache, Idaho, an unincorporated community
* Cache, Illinois, an unincorporated community
* Cache, Oklahoma, a city in Comanche County
* Cache, Utah, Cache County, Utah
* Cache County ...
as a result of prior online browsing by the user or explicitly by a browser configured to keep local copies of certain web pages, which are updated when the browser is in the online state, either by checking that the local copies are up-to-date at regular intervals or by checking that the local copies are up-to-date whenever the browser is switched to the online. One such web browser is
Internet Explorer
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical user interface, graphical web browsers developed by Microsoft which was used in the Microsoft Wind ...
. When pages are added to the Favourites list, they can be marked to be "available for offline browsing". Internet Explorer will download local copies of both the marked page and, optionally, all of the pages that it links to. In Internet Explorer version 6, the level of direct and indirect links, the maximum amount of local disc space allowed to be consumed, and the schedule on which local copies are checked to see whether they are up-to-date, are configurable for each individual Favourites entry.
For communities that lack adequate Internet connectivity—such as developing countries, rural areas, and prisons—offline information stores such as WiderNet's
eGranary
The eGranary Digital Library is a product of the WiderNet Project, a non-profit aimed at providing access to information technology and library services in developing countries.
History
In 2000 Cliff Missen and Michael McNulty founded WiderNet ...
Digital Library (a collection of approximately thirty million educational resources from more than two thousand web sites and hundreds of CD-ROMs) provide offline access to information. More recently, the
Internet Archive
The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge". It provides free public access to collections of digitized materials, including websites, software applications/games, music, ...
announced an offline server project intended to provide access to material on inexpensive servers that can be updated using USB sticks and SD cards.
Offline storage
Likewise,
offline storage
Computer data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers.
The central processing unit (CPU) of a compute ...
is
computer data storage
Computer data storage is a technology consisting of computer components and Data storage, recording media that are used to retain digital data (computing), data. It is a core function and fundamental component of computers.
The central pro ...
that is not "available for immediate use on demand by the system without human intervention". Additionally, an otherwise online system that is powered down may be considered offline.
Offline messages
With the growing communication tools and media, the words offline and online are used very frequently. If a person is active over a messaging tool and is able to accept the messages it is termed as online message and if the person is not available and the message is left to view when the person is back, it is termed as offline message. In the same context, the person's availability is termed as online and non-availability is termed as offline.
File systems
In the context of file systems, "online" and "offline" are synonymous with "mounted" and "not mounted". For example, in
file systems' resizing capabilities, "online grow" and "online shrink" respectively mean the ability to increase or decrease the space allocated to that file system without needing to unmount it.
Generalisations
Online and offline distinctions have been generalised from computing and telecommunication into the field of human interpersonal relationships. The distinction between what is considered online and what is considered offline has become a subject of study in the field of
sociology
Sociology is a social science that focuses on society, human social behavior, patterns of Interpersonal ties, social relationships, social interaction, and aspects of culture associated with everyday life. It uses various methods of Empirical ...
.
The distinction between online and offline is conventionally seen as the distinction between
computer-mediated communication
Computer-mediated communication (CMC) is defined as any human communication that occurs through the use of two or more electronic devices. While the term has traditionally referred to those communications that occur via computer-mediated formats ...
and
face-to-face communication (e.g.,
face time
Face time is an English idiom for direct personal interaction or contact between two or more people at the same time and physical location. Face time therefore occurs in "real life" and contrasts primarily with interaction or contact which occurs ...
), respectively. Online is virtuality or
cyberspace, and offline is reality (i.e.,
real life or "meatspace"). Slater states that this distinction is "obviously far too simple".
To support his argument that the distinctions in relationships are more complex than a simple dichotomy of online versus offline, he observes that some people draw no distinction between an online relationship, such as indulging in
cybersex
Cybersex, also called computer sex, Internet sex, netsex and, colloquially, cyber or cybering, is a virtual sex encounter in which two or more people have long distance sex via electronic video communication (webcams, VR headsets, etc) and other e ...
, and an offline relationship, such as being
pen pal
Pen pals (or penpals, pen-pals, penfriends or pen friends) are people who regularly write to each other, particularly via postal mail. Pen pals are usually strangers whose relationship is based primarily, or even solely, on their exchange of le ...
s. He argues that even the
telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
can be regarded as an online experience in some circumstances, and that the blurring of the distinctions between the uses of various technologies (such as
PDA
PDA may refer to:
Science and technology
* Patron-driven acquisition, a mechanism for libraries to purchase books
*Personal digital assistant, a mobile device
* Photodiode array, a type of detector
* Polydiacetylenes, a family of conducting poly ...
versus mobile phone,
internet television
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air a ...
versus internet, and telephone versus
Voice over Internet Protocol
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...
) has made it "impossible to use the term ''online'' meaningfully in the sense that was employed by the first generation of Internet research".
Slater asserts that there are legal and regulatory pressures to reduce the distinction between online and offline, with a "general tendency to assimilate online to offline and erase the distinction," stressing, however, that this does not mean that online relationships are being reduced to ''pre-existing'' offline relationships. He conjectures that greater legal status may be assigned to online relationships (pointing out that contractual relationships, such as business transactions, online are already seen as just as "real" as their offline counterparts), although he states it to be hard to imagine courts awarding palimony to people who have had a purely online sexual relationship. He also conjectures that an online/offline distinction may be seen by people as "rather quaint and not quite comprehensible" within 10 years.
This distinction between ''online'' and ''offline'' is sometimes inverted, with online concepts being used to define and to explain offline activities, rather than (as per the conventions of the
desktop metaphor
In computing, the desktop metaphor is an interface metaphor which is a set of unifying concepts used by graphical user interfaces to help users interact more easily with the computer. The desktop metaphor treats the computer monitor as if it is t ...
with its desktops, trash cans, folders, and so forth) the other way around. Several cartoons appearing in ''
The New Yorker
''The New Yorker'' is an American weekly magazine featuring journalism, commentary, criticism, essays, fiction, satire, cartoons, and poetry. Founded as a weekly in 1925, the magazine is published 47 times annually, with five of these issues ...
'' have satirized this. One includes
Saint Peter
Saint Peter; he, שמעון בר יונה, Šimʿōn bar Yōnāh; ar, سِمعَان بُطرُس, translit=Simʿa̅n Buṭrus; grc-gre, Πέτρος, Petros; cop, Ⲡⲉⲧⲣⲟⲥ, Petros; lat, Petrus; ar, شمعون الصفـا, Sham'un ...
asking for a username and a password before admitting a man into Heaven. Another illustrates "the offline store" where "All items are actual size!", shoppers may "Take it home as soon as you pay for it!", and "Merchandise may be handled prior to purchase!"
See also
*
Computer networking
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ma ...
*
Extremely Online
*
NLS, or the "oN-Line System"
*
Offline reader
An offline reader (sometimes called an offline browser or offline navigator) is computer software that downloads e-mail, newsgroup posts or web pages, making them available when the computer is offline: not connected to a server. Offline readers ...
*
On the fly § Computer usage
*
Online algorithm
In computer science, an online algorithm is one that can process its input piece-by-piece in a serial fashion, i.e., in the order that the input is fed to the algorithm, without having the entire input available from the start.
In contrast, an o ...
*
Online and offline algorithms
*
Online editing
A collaborative real-time editor is a type of collaborative software or web application which enables real-time collaborative editing, simultaneous editing, or live editing of the same digital document, computer file or cloud-stored data – suc ...
and
offline editing
Offline editing is part of the post-production process of film making and television production in which raw footage is copied and the copy only is then edited, thereby not affecting the camera original film stock or video tape. Once the project ha ...
– the online/outline distinction in
video editing
Video editing is the manipulation and arrangement of video shots. Video editing is used to structure and present all video information, including films and television shows, video advertisements and video essays. Video editing has been dramaticall ...
*
Online game
An online game is a video game that is either partially or primarily played through the Internet or any other computer network available. Online games are ubiquitous on modern gaming platforms, including PC game, PCs, Console game, consoles and ...
s
*
Online identity
Internet identity (IID), also online identity or internet persona, is a social identity that an Internet user establishes in online communities and websites. It may also be an actively constructed presentation of oneself. Although some people cho ...
*
''Online'' (magazine)
*
Online volunteering
Virtual volunteering refers to volunteer activities completed, in whole or in part, using the Internet and a home, school, telecenter, or work computer or other Internet-connected device, such as a smartphone or a tablet. Virtual volunteering is a ...
*
Open access (publishing)
Open access (OA) is a set of principles and a range of practices through which research outputs are distributed online, free of access charges or other barriers. With open access strictly defined (according to the 2001 definition), or libre op ...
*
Presentity
The term presentity is a combination of two words - " presence" and "entity". It basically refers to an entity that has presence information associated with it; information such as status, reachability, and willingness to communicate.
Usage
The t ...
*
Reputation
The reputation of a social entity (a person, a social group, an organization, or a place) is an opinion about that entity typically as a result of social evaluation on a set of criteria, such as behavior or performance.
Reputation is a ubiquitous ...
*
Website mirroring software
An offline reader (sometimes called an offline browser or offline navigator) is computer software that downloads e-mail, newsgroup posts or web pages, making them available when the computer is offline: not connected to a server. Offline readers ...
References
*
{{refend
Computer jargon
Internet terminology