Cache (computing)In computing, a cache ( ) is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A cache hit occurs when the requested data can be found in a cache, while a cache miss occurs when it cannot.
Virtual memoryVirtual memory combines active RAM and inactive memory on DASD to form a large range of contiguous addresses.In computing, virtual memory, or virtual storage, is enabled by a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very large (main) memory".
Operating systemAn operating system (OS) is system software that manages computer hardware and software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, peripherals, and other resources.
Demand pagingIn computeroperating systems, demand paging (as opposed to anticipatory paging) is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only when an attempt is made to access it and that page is not already in memory (i.e., if a page fault occurs).
Memory protection unitA memory protection unit (MPU) is a computer hardware unit that provides memory protection. It is usually implemented as part of the central processing unit (CPU). MPU is a trimmed down version of memory management unit (MMU) providing only memory protection support. It is usually implemented in low power processors that require only memory protection and do not need the full-fledged feature of a MMU like virtual memory management.
Virtual address spaceIn computing, a virtual address space (VAS) is an area of contiguous virtual memory locations, called virtual addresses, which an operating system makes available to a process for executing instructions and storing data, and which it maps to the address space of physical addresses in a computer's hardware memory.
Physical addressIn computing, a physical address (also real address, or binary address), is a memory address that is represented in the form of a binary number on the address bus circuitry in order to enable the data bus to access a particular item (byte, word, etc.) of main memory, or a register of memory-mapped I/O device.
Real-time operating systemA real-time operating system (RTOS) is an operating system (OS) for real-time computing applications that processes data and events that have critically defined time constraints. An RTOS mainly targets resource constrained devices like microcontrollers. It is distinct from a time-sharing operating system, such as Unix, which manages the sharing of system resources with a scheduler, data buffers, or fixed task prioritization in multitasking or multiprogramming environments.
Computer memoryComputer memory stores information, such as data and programs, for immediate use in the computer; instructions fetched by the computer, and data fetched and stored by those instructions, are located in computer memory. The terms memory, main memory, and primary storage are also used for computer memory. Computer memory is often referred to as RAM, meaning random-access memory, although some older forms of computer memory, such as drum memory, are not random-access.
InterruptIn digital computers, an interrupt is a request for the processor to interrupt currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an interrupt handler (or an interrupt service routine, ISR) to deal with the event.
Computer hardwareComputer hardware, commonly shortened to hardware, includes the physical parts of a computer, such as the central processing unit (CPU), random-access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices such as a monitor, mouse, keyboard, and speakers. By contrast, software is a set of written instructions that can be stored and run by hardware.
Computer architectureIn computer science and computer engineering, a computer architecture is the conceptual design and operational structure of a computer system that define how component parts are organized and interact to execute programs efficiently. It is often a general description that ignores precise implementation details. It covers the instruction set architecture, CPU microarchitecture, memory, and input/output systems.
Hard disk driveElectro-mechanical data storage device1. Front side of an HDD (Seagate Barracuda 320GB)2. Internal circuity of the above Seagate HDD3. Inside of an 2.5" and a 3.5" HDDA hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical computer data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material.*As an Amazon Associate I earn from qualifying purchases.