Accelerated Graphics Port

The Accelerated Graphics Port (also called Advanced Graphics Port, often abridged to AGP) is a high-speed point-to-point channel for attaching a graphics card to a computer's motherboard, primarily to help in the speeding up of 3D computer graphics. Since 2004, AGP is being increasingly phased out in favor of PCI Express. However, as of middle 2008 new AGP cards and motherboards are still obtainable for purchase, although OEM driver support is negligible.

Universal Serial Bus

In information technology, Universal Serial Bus (USB) is a serial bus standard to interface devices to a host computer. USB was intended to allow many peripherals to be connected using a single consistent interface socket and to get better the plug-and-play capabilities by allowing hot exchange, that is, by allowing devices to be connected and disconnected without rebooting the computer or rotating off the device. Other suitable features comprise providing power to low-consumption devices without the require for an external power provide and allowing many devices to be used without requiring manufacturer exact, individual device drivers to be installed.

USB is intended to replace many legacy varieties of serial and similar ports. USB can connect computer peripherals such as mouse, keyboards, PDAs, gamepads and joysticks, scanners, digital cameras, printers, personal media players, and flash drives. For many of those devices USB has become the standard connection method.

Industry Standard Architecture

The most common bus in the PC world, ISA stands for Industry Standard Architecture, and different many uses of the word "standard", in this case it in fact fits. The ISA bus is still a foundation in even the latest computers, despite the fact that it is mainly unchanged since it was prolonged to 16 bits in 1984! The ISA bus finally became a bottleneck to performance and was augmented with extra high-speed buses, but ISA persists because of the truly huge base of obtainable peripherals using the standard. Also, there are still many devices for which the ISA's speed is more than enough, and will be for a number of times to come

The choices made in important the main characteristics of the ISA bus--its width and speed--can be seen by looking at the processors with which it was balancing on early machines. The unique ISA bus on the IBM PC was 8 bits wide, shiny the 8 bit data width of the Intel 8088 processor's system bus, and ran at 4.77 MHz, again, the speed of the first 8088s. In 1984 the IBM AT was introduced using the Intel 80286; at the moment the bus was doubled to 16 bits (the 80286's data bus width) and increased to 8 MHz (the maximum speed of the original AT, which came in 6 MHz and 8 MHz versions).

Disk array

A disk array is a disk storage system which contains manifold disk drives. It is differentiated from a disk field, in that an array has cache memory and superior functionality, like RAID and virtualization.

Components of a characteristic disk array include:

* Disk array controllers
* Cache memories
* Disk enclosures
* Power supplies

Typically a disk array provides increased availability, resiliency and maintainability by using additional, redundant components (controllers, power supplies, fans, etc.), frequently up to the point at what time all single points of failure (SPOFs) are eliminated from the design. Additionally those mechanisms are often hot-swappable.

Typically, disk arrays are divided into five categories: NAS, Modular SAN arrays, Monolithic SAN arrays, Storage Virtualization and Utility SAN Arrays.

Solid-state drive

A solid-state drive (SSD) is a data storage device that uses solid-state memory to store constant data. Unlike flash-based memory cards and USB flash drives, a SSD emulates a hard disk drive interface, thus easily replacing it in the majority applications. An SSD using SRAM or DRAM (instead of flash memory) is frequently called a RAM-drive.

The unique usage of the term solid-state (from solid-state physics) refers to the employ of semiconductor devices quite than electron tubes, but has in this background been adopted to differentiate solid-state electronics from electromechanical devices as well. With no moving parts, solid-state drives are intrinsically less fragile than hard disks and so also silent (unless a cooling fan is used); as there are no mechanical delays, they typically enjoy low access time and latency.

SSDs have begun to appear in laptops, although they are at present considerably more expensive per unit of capacity than hard drives.

Firmware

Firmware is a special-purpose module of low-level software that serves two purposes. Initial, it acts like BIOS, enabling the device to get stock of its capabilities and to make those capabilities functional. Next, it coordinates the activities of the hardware throughout normal operation and contains programming constructs used to do those operations. For example, in a typical modem, the firmware will be a issue in establishing the modem's data rate, command set recognition, and particular feature completion.

Firmware is stored in a particular type of memory chip that doesn't misplace its storage capabilities when power is detached or lost. This non-volatile memory is classified as "read-only" memory (ROM) since the user, during usual operation, cannot modify the information stored there. The basic type of chip is called a PROM, which is programmable by some technician who has a programming console. An essential PROM receives one version of firmware. That code is "burned in" to the PROM and cannot be distorted. To update the firmware, the PROM must be actually removed from the device and replaced with a new chip.

Hard Disk Drive(HDD)

A hard disk drive (HDD), usually referred to as a hard drive, hard disk, or fixed disk drive, is a non-volatile storage device which stores digitally encoded data on quickly rotating platters with magnetic surfaces. Severely speaking, "drive" refers to a device separate from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk. Early HDDs had detachable media; however, an HDD today is classically a sealed unit (apart from for a filtered vent hole to make equal air pressure) with fixed media.

The device that reads and writes data on a hard disk. Hard disk drives (HDDs) for PCs usually have sought times of about 12 milliseconds or less. Many disk drives improve their performance during a technique called caching.

There are more than a few interface standards for passing data between a hard disk and a computer. The most common are IDE and SCSI.

Hard disk drives are sometimes called Winchester drives, Winchester being the name of one of the first well-liked hard disk drive technologies urbanized by IBM in 1973.

Floppy disk

A floppy disk is a data storage medium that is collected of a disk of thin, flexible ("floppy") magnetic storage medium covered in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD, the initials of which should not be perplexed with "fixed disk drive", which is one more term for a hard disk drive.

Floppies come in three essential sizes:

8-inch: The first floppy disk design, imaginary by IBM in the late 1960s and used in the early 1970s as first a read-only format and then as a read-write format. The typical desktop/laptop computer does not employ the 8-inch floppy disk.

5¼-inch: The ordinary size for PCs made before 1987 and the precursor to the 8-inch floppy disk. This type of floppy is usually capable of storing between 100K and 1.2MB (megabytes) of data. The most ordinary sizes are 360K and 1.2MB.

3½-inch: Floppy is something of a misnomer for these disks, as they are covered in an unbending envelope. In spite of their small size, microfloppies contain a larger storage capacity than their cousins -- from 400K to 1.4MB of data. The most common sizes for PCs are 720K (double-density) and 1.44MB (high-density). Macintoshes hold up disks of 400K, 800K, and 1.2MB.

Blu-ray Disc

Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format together developed by the Blu-ray Disc Association (BDA), a collection of the world's most important consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to allow recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of conventional DVDs and can grasp up to 25GB on a single-layer disc and 50GB on a dual-layer disc.

While present optical disc technologies such as DVD, DVD±R, DVD±RW, and DVD-RAM rely on a red laser to read and write data, the new format uses a blue-violet laser in its place, hence the name Blu-ray. In spite of the different type of lasers used, Blu-ray products can easily be completed backwards compatible with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. The advantage of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it probable to focus the laser spot with even greater precision. This allows data to be crowded more tightly and stored in less space, so it's possible to fit more data on the disc still though it's the same size as a CD/DVD. This mutually with the change of numerical aperture to 0.85 is what enables Blu-ray Discs to grasp 25GB/50GB.

DVD

DVDr (also known as "Digital Versatile Disc" or "Digital Video Disc") is a popular optical disc storage media format. Its major uses are video and data storage. Most DVDs are of the similar dimensions as compact discs (CDs) but store more than six times as much data.

Variations of the term DVD often explain the way data is stored on the discs: DVD-ROM has data which can merely be read and not written, DVD-R and DVD+R can only record data one time and then function as a DVD-ROM. DVD-RW and DVD+RW can both record and remove data multiple times. The wavelength used by normal DVD lasers is 650 nm, and thus has a red color.

DVD-Video and DVD-Audio discs respectively refer to correctly formatted and structured audio and video content. Other types of DVDs, counting those with video content, may be referred to as DVD-Data discs. After that generation High definition optical formats also use a disc identical in some aspects yet more higher than a DVD, such as Blu-ray Disc, the original DVD is infrequently given the retronym SD DVD (for standard definition

Peripheral Component Interconnect

PCI (Peripheral Component Interconnect) is an industry condition for connecting hardware devices to a computer's central processor. Both Ethernet and Wi-Fi network adapters for desktop and notebook computers usually utilize PCI.

PCI defines the electrical characteristics and signal protocol used for two devices to converse over a computer's central bus. PCI network adapters and other devices be in more than a few different shapes and sizes called "form factors."

Besides traditional Ethernet PCI cards that manufacturers pre-install in desktop computers, ordinary PCI form factors for consumer network devices are:

* Card Bus - also Wi-Fi or Ethernet PC Card (also known as PCMCIA or "credit card") network adapters
* Mini PCI - Wi-Fi network cards fixed inside notebook computers

Internal bus

In computer architecture, a bus is a subsystem so as to transfers data between computer components within a computer or between computers. Unlike a point-to-point connection, a bus can rationally connect several peripherals in excess of the same set of wires. Each bus defines its set of connectors to bodily plug devices, cards or cables jointly.

Early computer buses were literally similar electrical buses with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a equivalent electrical bus. Modern computer buses can use both parallel and bit-serial connections, and can be wired in also a multidrop (electrical parallel) or daisy chain topology, or linked by switched hubs, as in the container of USB.

Computer fan

A computer fan can be some fan inside a computer case used for cooling purposes, and may refer to fans that sketch cooler air into the container from the outside, drive out warm air from inside, or move air across a heat sink to cool a exacting component. The use of fans and/or other hardware to cool a computer is sometimes referred to as lively cooling.

Used to inferior the temperature of the computer; a fan is almost always attached to the CPU, and the computer case will usually have several fans to maintain a constant airflow. Liquid cooling can also be used to cool a computer, while it focuses more on individual parts quite than the overall temperature within the chassis.

Video Display Controller

A video display controller which can display foregrounds as well as backgrounds of display patterns on a screen of a video display unit in a plurality of colors . The video display controller comprises a plurality of color in order registers, in each of which a pair of color code data representative of center and backdrop colors of one display pattern are stored. A memory is provided for storing a plurality of prototype data, a plurality of pattern name data every designating one of the display patterns to be displayed on a own one of display portions of the screen, and a plurality of color assortment data each equivalent to a respective one of the display portions.

A sequence controller in sequence reads the pattern data chosen by the pattern name data and the color selection data in agreement with synchronization signals. A color collection control logic circuit selects one of the color information registers in harmony with the color selection data interpret from the memory, and reads one of the pair of color code data from the selected color in sequence register. A color signal generator generates a color signal in accordance with the color code data read from the register and provisions it to the video display unit.

RAID Storage Controllers

The storage controllers are the set of mechanism that allows you to store programs and data on your PC. The term "permanent" is used to store the data enduringly into the system memory, while temporary holds data awaiting your PC is on. The storage controllers are a very significant part of the PC after all they hold the programs and data on your PC.

The storage subsystem consists of two types of hardware. the storage devices, which are the drives that grasp data. Usually, the systems contain one or more of the following storage devices: one or more hard disk, CD-ROM or CD-RW or DVD drives, and Floppy disk drives, Tape drives and additional media drives, such as Zip disk drives and consequently. Each of these storage devices talks to the PC through an interface, which is used as an internal communication channel used to move information to and from the storage device. The boundary runs between the controller on the storage device, and a matching controller inside the PC system.

The dissimilar types of Storage Controllers in your system are Floppy disk controller, for floppy disk drives, SCSI controller, for SCSI hard disks & CD-ROM drives, Universal Serial Bus controller, for USB devices. A number of of these controllers, such as floppy controllers, are regularly built on the chipset of the motherboard. Industry-standard consumer generally uses the IDE/ATA interface for hard disks, the floppy interface for the floppy drive and USB together storage devices. There are many different parameter of the storage subsystem that has an effect on the capabilities of the PC as a entire

ROM

Read-only memory (usually known by its acronym, ROM) is a class of storage space media used in computers and other electronic devices. Since data stored in ROM cannot be customized, it is mainly used to distribute firmware (software that is very closely tied to exact hardware and improbable to require frequent updates).

Modern semiconductor ROM chips are not right away distinguishable from similar chips like RAM modules, apart from by the part numbers printed on the package.

In its strictest sense, ROM refers only to mask ROM (the oldest type of solid state ROM), which is made-up with the desired data enduringly stored in it, and thus can never be adapted. However, more contemporary types such as EPROM and flash EEPROM can be erased and re-programmed many times; they are still described as "read-only memory" because the reprogramming process is usually infrequent, comparatively slow, and often does not authorize random access writes to individual memory locations, which are likely when reading a ROM.

There are five basic ROM types:

* ROM
* PROM
* EPROM
* EEPROM
* Flash memory

Motherboard

A motherboard is the central or primary printed circuit board (PCB) creation up a multifaceted electronic system, such as a modern computer. It is also known as a mainboard, baseboard, system board, planar board, or, on Apple computers, a logic board, and is now and then abbreviated carelessly as mobo.

Most motherboards shaped today are intended for so-called IBM-compatible computers, which detained over 96% of the global personal computer market in 2005.Motherboards for IBM-compatible computers are specially covered in the PC motherboard article.

A motherboard, like a backplane, provides the electrical relations by which the other mechanism of the system converse, but unlike a backplane also contains the central dispensation unit and other subsystems such as real time clock, and some tangential interfaces.

A typical desktop computer is built with the microprocessor, main memory, and other necessary components on the motherboard. Other components such as external storage, controllers for video display and sound, and peripheral devices are classically attached to the motherboard via edge connectors and cables, although in modern computers it is more and more common to integrate these "peripherals" into the motherboard.

Central Processing Unit

1. The portion of a computer that includes circuits controlling the interpretation and execution of instructions.

2. The portion of a computer that executes programmed instructions, performs arithmetic and logical operations on data, and controls input / output functions. Synonym central processor.

3. Abbreviation for communications processor unit. A computer embedded in a communications system, i.e., the portion of a digital communications switch that executes programmed instructions, performs arithmetic and logical operations on signals, and controls input/output functions.

The processor is truly the computer --- it is wired to compute arithmetic and related operations on numbers that it can hold in its data registers. A processor is also called a Central Processing Unit (CPU).

* The data registers hold numbers for computation, as noted earlier.

* There is a simple clock --- a pulse generator --- that helps the Control Unit do instructions in proper time steps.

* The arithmetic-logic unit (ALU) holds the wiring for doing arithmetic on the numbers held in the data registers. (Review the addition example above.)

* The control unit holds wiring that triggers the arithmetic operations in the ALU. How does the control unit know to request an addition or a subtraction? The answer is: it obtains instructions, one at a time, that have been stored in primary storage.

* The instruction counter is a register that tells the control unit where to find the instruction that it must do. (The details will be explained shortly.)

* The instruction register is where the instruction can be copied and held for study by the control unit,

* The address buffer and data buffer are two registers that are a ``drop-off'' point when the processor wishes to copy information from a register to primary storage (or read information from primary storage to a register). We study them later.

* The interrupt register is studied much later.

Semiconductors

Semiconductors are unique substances, which, under different conditions, can act as either conductors or insulators of electricity. Semiconductor processors turn one of these substances—silicon—into microchips, also known as integrated circuits. These microchips contain millions of tiny electronic components and are used in a wide range of products, from personal computers and cellular telephones to airplanes and missile guidance systems.

To manufacture microchips, semiconductor processors start with cylinders of silicon called ingots. First, the ingots are sliced into thin wafers. Using automated equipment, workers or robots polish the wafers, imprint precise microscopic patterns of the circuitry onto them using photolithography, etch out patterns with acids, and replace the patterns with conductors, such as aluminum or copper. The wafers then receive a chemical bath to make them smooth, and the imprint process begins again on a new layer with the next pattern. A complex chip may contain more than 20 layers of circuitry. Once the process is complete, wafers are then cut into individual chips, which are enclosed in a casing and shipped to equipment manufacturers.

The manufacturing and slicing of wafers to create semiconductors takes place in cleanrooms—production areas that are kept free of all airborne matter because the circuitry on a chip is so small that even microscopic particles can make it unusable. All semiconductor processors working in cleanrooms must wear special lightweight outer garments known as “bunny suits”. These garments fit over clothing to prevent lint and other particles from contaminating the cleanroom.

There are two types of semiconductor processors: operators and technicians. Operators start and monitor the equipment that performs the various production tasks. They spend the majority of their time at computer terminals, monitoring the operation of equipment to ensure that each of the tasks in the production of the wafer is performed correctly. Operators may also transfer wafer carriers from one station to the next, though the lifting of heavy wafer carriers is done by robots in most new fabricating plants.

Technicians are generally more experienced workers who troubleshoot production problems and make equipment adjustments and repairs. They take the lead in assuring quality control and in maintaining equipment. They also test completed chips to make sure they work properly. To keep equipment repairs to a minimum, technicians perform diagnostic analyses and run computations. For example, technicians may determine if a flaw in a chip is due to contamination and peculiar to that wafer, or if the flaw is inherent in the manufacturing process.

Mouse

• The mouse is present in virtually every office environment. Handed versions of mouses are designed specifically to the contours of either the right or left hand.
• Placing the mouse, trackball, or other input device too far away, too low, or too much on one side can cause shoulder, wrist, elbow, and forearm discomfort. Placing the input device directly in your immediate reach zone offers natural comfort and maximum hand-to-eye coordination.
• Do not bend your wrist upward. Make sure you are sitting high enough for the workstation to be slightly below elbow height so that your hand rests naturally on the mouse.
• Mousing demands a certain level of surface stability; if used on a keyboard tray, the tray should not wobble or tip.
• A trackball has an exposed ball that you manipulate with your fingers. It requires the use of different muscle and tendon groups than does a mouse, and can add variety to your manipulation of computer information. Some trackball designs, however, may cause discomfort and possible injury to the area around your thumb, which stretches and reaches to maneuver the trackball.
• Test different models of mousing devices, trackball or other input devices. Consider the shape and size of the devices, how comfortably it fits into your hand, ease of operation, and any special features that might make your job easier.

Memeory Card Reader

A memory card reader is a device used for communication with a smart card or a flash memory card. A business card reader is a scanning device used to scan and electronically save business cards. A magnetic card reader is a device used to scan cards containing magnetic data strips. A punched card reader is a device used to read holes in punched cardboard cards. A memory card reader is a device, typically having a USB interface, for accessing the data on a memory card such as a CompactFlash (CF), Secure Digital (SD) or Multimedia Card (MMC). Most card readers also offer write capability, and together with the card, this can function as a pen drive. Today card readers can be categorized into three by the type and quantity of the card slots: single card reader (e.g. 1x SD-only), multi card reader (e.g. 9-in-1) and series card reader (e.g. 4x SD only). However, there are some kinds of memory cards with USB functions that do not need the card reader, such as the Intelligent Stick memory card, which can plug directly into a USB slot.

Printer

Usage Tips Make sure the power management and duplexing features of your printer have been “enabled” at the printer and that duplexing is the default setting within each user’s software. Set the “waittime” prior to sleep mode as short as possible, consistent with user needs.
Even for printers with a low-power sleep mode, you can save more energy if you manually shutthem off completely at night and on weekends. A few printer models do not have a manual on/off switch; these can be shut off using an external “power strip” (surge protector).
Networked systems that allow several nearby users to share a single (faster) printer generally save time, cost, and energy compared with each computer having a dedicated printer.
In some cases, an older printer that does not have an ENERGY STAR sleep mode can still be power-managed using an external control device. External controls switch the printer off(rather than into sleep mode) after a preset time, and switch it on again when a “print”signal is received. EPA’s web site and hotline provide a list of external printer controls.

Surge Protector

A surge protector is an application designed to protect electrical devices from voltage spikes. A surge protector attempts to regulate the energy supplied to an emotional device by either blocking or by shorting to ground voltages above a safe entrance. The following text discusses specifications and workings relevant only to the type of minder that diverts (shorts) a voltage spike to ground.

Webcam

Webcams are small cameras, whose images can be accessed using the World Wide Web, instant messaging, or a PC video conferencing submission. The term webcam is also used to portray the low-resolution digital video cameras designed for such purposes, but which can also be used to record in a non-real-time manner.

Web-accessible cameras absorb a digital camera which uploads images to a web server, either incessantly or at regular intervals. This may be achieved by a camera friendly to a PC, or by committed hardware. Videoconferencing cameras normally take the form of a small camera associated directly to a PC. Analog cameras are also sometimes used, connected to a video incarcerate card and then honestly or circuitously to the internet.

Scanner

In computing, a scanner is a tool that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop scanner where the file is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, were temporarily popular but are now less common due to the intricacy of obtaining a high-quality image. instinctively driven scanners that move the document are naturally used for large-format documents, where a flatbed design would be unreasonable.

Modern scanners logically use charge-coupled device (CCD) or Contact Image Sensor (CIS) as the image sensor, whereas older drum scanners use a photomultiplier tube as the image sensor. A gyratory scanner, used for high-speed document scanning, is another type of drum scanner, using a CCD array instead of a photomultiplier. Other types of scanners are terrestrial scanners, which take photographs of books and documents, and 3D scanners, for producing three-dimensional models of objects.

Another category of scanner is digital camera scanners, which are based on the concept of reprographic cameras. Due to increasing declaration and new features such as anti-shake, digital cameras have become an pretty alternative to regular scanners. While still having disadvantages compared to established scanners, digital cameras offer advantages in speed and portability..

Video Card

A video card, also referred to as a graphics accelerator card, display adapter, graphics card, and plentiful other terms, is an item of personal computer hardware whose function is to produce and output images to a exhibit. It operates on similar principles as a sound card or other marginal devices.

The term is usually used to refer to a split, dedicated increase card that is plugged into a slot on the computer's motherboard, as divergent to a graphics controller incorporated into the motherboard chipset. An integrated graphics controller may be referred to as an "integrated graphics processor" (IGP).

Some video cards offer added functions, such as video capture, TV tuner adapter, MPEG-2 and MPEG-4 decoding or even FireWire, mouse, light pen, joystick connectors, or even the capacity to connect two monitors.

RAM

Random access memory is a type of computer data storage space. Today it takes the form of included circuits that allow the stored data to be accessed in any order, i.e. at random. The word random thus refers to the detail that any piece of data can be returned in a constant time, despite of its physical location and whether or not it is related to the earlier piece of data.

This contrasts with storage mechanisms such as tapes, charismatic discs and optical discs, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the rescue time varies depending on the physical location of the next item.

The word RAM is mostly associated with explosive types of memory (such as DRAM memory modules), where the information is lost after the power is switched off. However, many other types of memory are RAM as well, including most types of ROM and a type of flash memory called NOR-Flash.

Computer

A computer is a machine that manipulates data according to a list of directions. The first devices that be like modern computers date to the mid-20th century (around 1940 - 1945), although the computer concept and various machines similar to computers existed previous. Early electronic computers were the size of a large room, consuming as much power as numerous hundred modern personal computers. Modern computers are based on miniature integrated circuits and are millions to billions of times more competent while occupying a division of the space. Today, simple computers may be made small enough to fit into a timepiece and be powered from a watch battery. Personal computers in various forms are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the surrounded computer. Embedded computers are small, simple devices that are used to control other devices — for example, they may be found in machines ranging from fighter aircraft to manufacturing robots, digital cameras, and children's toys.

The capability to store and execute lists of instructions called programs makes computers extremely adaptable and distinguishes them from calculators. The Church–Turing thesis is a arithmetic statement of this flexibility: any computer with a certain minimum competence is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with competence and complication ranging from that of a personal digital subordinate to a supercomputer are all able to perform the same computational tasks given enough time and storage capability.

CPU

A Central Processing Unit (CPU), or occasionally just called processor, is a explanation of a class of logic machines that can perform computer programs. This broad definition can simply be applied to many early computers that existed long before the term "CPU" ever came into extensive usage. However, the term itself and its initialism have been in use in the computer business at least since the early 1960s. The form, design and execution of CPUs have changed noticeably since the earliest examples, but their essential operation has remained much the same.

Early CPUs were custom-designed as a part of a larger, typically one-of-a-kind, computer. However, this costly method of designing custom CPUs for a particular submission has largely given way to the development of mass-produced processors that are suited for one or many purposes. This homogeny trend generally began in the era of discrete transistor mainframes and minicomputers and has speedily accelerated with the popularization of the integrated circuit (IC). The IC has allowed increasingly complex CPUs to be intended and manufactured in very small spaces. Both the neatness and regularity of CPUs have increased the incidence of these digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in everything from automobiles to cell phones to children's toys.