Personal computer

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Children being taught how to use a notebook (portable laptop) personal computer; an older (1990s-era) desktop personal computer's CRT monitor, keyboard, and mouse are visible in the background.
An artist's depiction of a 2000s-era desktop-style personal computer, which includes a metal case with the computing components, a display monitor and a keyboard (mouse not shown).

A personal computer (PC) is a multi-purpose computer whose size, capabilities, and price make it feasible for individual use.[1] Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers.

Institutional or corporate computer owners in the 1960s had to write their own programs to do any useful work with the machines. While personal computer users may develop their own applications, usually these systems run commercial software, free-of-charge software ("freeware"), which is most often proprietary, or free and open-source software, which is provided in "ready-to-run", or binary, form. Software for personal computers is typically developed and distributed independently from the hardware or operating system manufacturers.[2] Many personal computer users no longer need to write their own programs to make any use of a personal computer, although end-user programming is still feasible. This contrasts with mobile systems, where software is often only available through a manufacturer-supported channel,[3] and end-user program development may be discouraged by lack of support by the manufacturer.[4]

Since the early 1990s, Microsoft operating systems and Intel hardware dominated much of the personal computer market, first with MS-DOS and then with Microsoft Windows. Alternatives to Microsoft's Windows operating systems occupy a minority share of the industry. These include Apple's macOS and free and open-source Unix-like operating systems.



"PC" is an initialism for "personal computer". The IBM Personal Computer incorporated the designation in its model name. It is sometimes useful to distinguish personal computers of the "IBM Personal Computer" family from personal computers made by other manufacturers. For example, "PC" is used in contrast with "Mac", an Apple Macintosh computer.[5][6][7][8] Since none of these Apple products were mainframes or time-sharing systems, they were all "personal computers" and not "PC" (brand) computers.





In the history of computing, early experimental machines could be operated by a single attendant. For example, ENIAC which became operational in 1946 could be run by a single, albeit highly trained, person.[10] This mode pre-dated the batch programming, or time-sharing modes with multiple users connected through terminals to mainframe computers. Computers intended for laboratory, instrumentation, or engineering purposes were built, and could be operated by one person in an interactive fashion. Examples include such systems as the Bendix G15 and LGP-30of 1956, and the Soviet MIR series of computers developed from 1965 to 1969.[citation needed] By the early 1970s, people in academic or research institutions had the opportunity for single-person use of a computer system in interactive mode for extended durations, although these systems would still have been too expensive to be owned by a single person.

The personal computer was made possible by major advances in semiconductor technology. In 1959, the silicon integrated circuit (IC) chip was developed by Robert Noyce at Fairchild Semiconductor,[11] and the metal-oxide-semiconductor (MOS) transistor was developed by Mohamed Atalla and Dawon Kahng at Bell Labs.[12] The MOS integrated circuit was commercialized by RCA in 1964,[13] and then the silicon-gate MOS integrated circuit was developed by Federico Faggin at Fairchild in 1968.[14] Faggin later used silicon-gate MOS technology to develop the first single-chip microprocessor, the Intel 4004, in 1971.[15] The first microcomputers, based on microprocessors, were developed during the early 1970s. Widespread commercial availability of microprocessors, from the mid-1970s onwards, made computers cheap enough for small businesses and individuals to own.

In what was later to be called the Mother of All Demos, SRI researcher Douglas Engelbart in 1968 gave a preview of features that would later become staples of personal computers: e-mail, hypertext, word processing, video conferencing, and the mouse. The demonstration required technical support staff and a mainframe time-sharing computer that were far too costly for individual business use at the time.


Micral N was the earliest commercial, non-kit microcomputer based on a microprocessor, the Intel 8008. It was built starting in 1972, and a few hundred units were sold. This had been preceded by the Datapoint 2200 in 1970, for which the Intel 8008 had been commissioned, though not accepted for use. The CPU design implemented in the Datapoint 2200 became the basis for x86 architecture[16] used in the original IBM PC and its descendants.[17]




Also in 1973 Hewlett Packard introduced fully BASIC programmable microcomputers that fit entirely on top of a desk, including a keyboard, a small one-line display, and printer. The Wang 2200 microcomputer of 1973 had a full-size cathode ray tube (CRT) and cassette tape storage.[21] These were generally expensive specialized computers sold for business or scientific uses.

Altair 8800 computer



The three personal computers referred to by Byte Magazine as the "1977 Trinity" of home computing: The Commodore PET, the Apple II, and the TRS-80 Model I.


In 1977 the Heath company introduced personal computer kits known as Heathkits, starting with the Heathkit H8, followed by the Heathkit H89 in late 1979. With the purchase of the Heathkit H8 you would obtain the chassis and CPU card to assemble yourself, additional hardware such as the H8-1 memory board that contained 4k of RAM could also be purchased in order to run software. The Heathkit H11 model was released in 1978 and was one of the first 16-bit personal computers, however due to its high retail cost of $1,295 was discontinued in 1982.[31][32][33]

IBM 5150, released in 1981

During the early 1980s, home computers were further developed for household use, with software for personal productivity, programming and games. They typically could be used with a television already in the home as the computer display, with low-detail blocky graphics and a limited color range, and text about 40 characters wide by 25 characters tall. Sinclair Research,[34] a UK company, produced the ZX Series‍—‌the ZX80 (1980), ZX81 (1981), and the ZX Spectrum; the latter was introduced in 1982, and totaled 8 million unit sold. Following came the Commodore 64, totaled 17 million units sold [35][36] and the Amstrad CPC series (464–6128).


Somewhat larger and more expensive systems were aimed at office and small business use. These often featured 80-column text displays but might not have had graphics or sound capabilities. These microprocessor based systems were still less costly than time-shared mainframes or minicomputers.


IBM's first PC was introduced Aug. 12, 1981.[39]


An increasingly important set of uses for personal computers relied on the ability of the computer to communicate with other computer systems, allowing interchange of information. Experimental public access to a shared mainframe computer system was demonstrated as early as 1973 in the Community Memory project, but bulletin board systems and online service providers became more commonly available after 1978. Commercial Internet service providers emerged in the last 1980's, giving public access to the rapidly growing network.

In 1991, the World Wide Web was made available for public use. The combination of powerful personal computers with high resolution graphics and sound, with the infrastructure provided by the Internet, and the standardization of access methods of the Web browsers, established the foundation for a significant fraction of modern life, from bus time tables through unlimited distribution of free pornography through to online user-edited encyclopedias.






Desktop computer[edit]

A Dell OptiPlex desktop computer

Before the widespread use of PCs, a computer that could fit on a desk was remarkably small, leading to the "desktop" nomenclature. More recently, the phrase usually indicates a particular style of computer case. Desktop computers come in a variety of styles ranging from large vertical tower cases to small models which can be tucked behind or rest directly beneath (and support) LCD monitors.

While the term "desktop" often refers to a computer with a vertically aligned computer tower case, these varieties usually rest on the ground or underneath desks. Despite this seeming contradiction, the term "desktop" does typically refer to these vertical tower cases as well as the horizontally aligned models which are designed to literally rest on top of desks and are therefore more appropriate to the "desktop" term, although both types qualify for this "desktop" label in most practical situations aside from certain physical arrangement differences. Both styles of these computer cases hold the systems hardware components such as the motherboard, processor chip, other internal operating parts. Desktop computers have an external monitor with a display screen and an external keyboard, which are plugged into USB ports on the back of the computer case. Desktop computers are popular for home and business computing applications as they leave space on the desk for multiple monitors.

A gaming computer is a desktop computer that generally comprises a high-performance video card, processor and memory, to improve the speed and responsiveness of demanding video games.[42]

An all-in-one computer (also known as single-unit PCs) is a desktop computer that combines the monitor and processor within a single unit. A separate keyboard and mouse are standard input devices, with some monitors including touchscreen capability. The processor and other working components are typically reduced in size relative to standard desktops, located behind the monitor, and configured similarly to laptops.

A nettops computer was introduced by Intel in February 2008, characterized by low cost and lean functionality. These were intended to be used with an Internet connection to run Web browsers and Internet applications.


A Home theater PC (HTPC) combines the functions of a personal computer and a digital video recorder. It is connected to a TV set or an appropriately sized computer display, and is often used as a digital photo viewer, music and video player, TV receiver, and digital video recorder. HTPCs are also referred to as media center systems or media servers. The goal is to combine many or all components of a home theater setup into one box. HTPCs can also connect to services providing on-demand movies and TV shows. HTPCs can be purchased pre-configured with the required hardware and software needed to add television programming to the PC, or can be assembled from components.


The potential utility of portable computers was apparent early on. Alan Kay described the Dynabook in 1972, but no hardware was developed. The Xerox NoteTaker was produced in a very small experimental batch around 1978. In 1975, the IBM 5100 could be fit into a transport case, making it a portable computer, but it weighed about 50 pounds.

Before the introduction of the IBM PC, portable computers consisting of a processor, display, disk drives and keyboard, in a suit-case style portable housing, allowed users to bring a computer home from the office or to take notes at a classroom. Examples include the Osborne 1 and Kaypro; and the Commodore SX-64. These machines were AC powered and included a small CRT display screen. The form factor was intended to allow these systems to be taken on board an airplane as carry-on baggage, though their high power demand meant that they could not be used in flight. The integrated CRT display made for a relatively heavy package, but these machines were more portable than their contemporary desktop equals. Some models had standard or optional connections to drive an external video monitor, allowing a larger screen or use with video projectors.

IBM PC-compatible suitcase format computers became available soon after the introduction of the PC, with the Compaq Portable being a leading example of the type. Later models included a hard drive to give roughly equivalent performance to contemporary desk top computers.

The development of thin plasma display and LCD screens permitted a somewhat smaller form factor, called the "lunchbox" computer. The screen formed one side of the enclosure, with a detachable keyboard and one or two half-height floppy disk drives, mounted facing the ends of the computer. Some variations included a battery, allowing operation away from AC outlets.[43]

Notebook computers such as the TRS-80 Model 100 and Epson HX-20 had roughly the plan dimensions of a sheet of typing paper (ANSI A or ISO A4). These machines had a keyboard with slightly reduced dimensions compared to a desktop system, and a fixed LCD display screen coplanar with the keyboard. These displays were usually small, with 8 to 16 lines of text, sometimes only 40 columns line length. However, these machines could operate for extended times on disposable or rechargeable batteries. Although they did not usually include internal disk drives, this form factor often included a modem for telephone communication and often had provisions for external cassette or disk storage. Later, clam-shell format laptop computers with similar small plan dimensions were also called "notebooks".


A laptop computer

A laptop computer is designed for portability with "clamshell" design, where the keyboard and computer components are on one panel, with a hinged second panel containing a flat display screen. Closing the laptop protects the screen and keyboard during transportation. Laptops generally have a rechargeable battery, enhancing their portability. To save power, weight and space, laptop graphics cards are in many cases integrated into the CPU or chipset and use system RAM, resulting in reduced graphics performance when compared to a desktop machine. For this reason, desktop computers are usually preferred over laptops for gaming purposes.

Unlike desktop computers, only minor internal upgrades (such as memory and hard disk drive) are feasible owing to the limited space and power available. Laptops have the same input and output ports as desktops, for connecting to external displays, mice, cameras, storage devices and keyboards. Laptops are also a little more expensive compared to desktops, as the miniaturized components for laptops themselves are expensive.

An Acer Aspire desktop replacement laptop

A desktop replacement computer is a portable computer that provides the full capabilities of a desktop computer. Such computers are currently large laptops. This class of computers usually includes more powerful components and a larger display than generally found in smaller portable computers, and may have limited battery capacity or no battery.[44]

Netbooks, also called mini notebooks or subnotebooks, were a subgroup of laptops[45][46] suited for general computing tasks and accessing web-based applications. Initially, the primary defining characteristic of netbooks was the lack of an optical disc drive, smaller size, and lower performance than full-size laptops. By mid-2009 netbooks had been offered to users "free of charge", with an extended service contract purchase of a cellular data plan.[47]


HP Compaq tablet PC with rotating/removable keyboard

A tablet uses a touchscreen display, which can be controlled using either a stylus pen or finger. Some tablets may use a "hybrid" or "convertible" design, offering a keyboard that can either be removed as an attachment, or a screen that can be rotated and folded directly over top the keyboard. Some tablets may use desktop-PC operating system such as Windows or Linux, or may run an operating system designed primarily for tablets. Many tablet computers have USB ports, to which a keyboard or mouse can be connected.


The LG G4, a typical smartphone

Smartphones are often similar to tablet computers, the difference being that smartphones always have cellular integration. They are generally smaller than tablets, and may not have a slate form factor.

Ultra-mobile PC[edit]

A Samsung Q1 Ultra UMPC

The ultra-mobile PC (UMP) is a small tablet computer. It was developed by Microsoft, Intel and Samsung, among others. Current UMPCs typically feature the Windows XP, Windows Vista, Windows 7, or Linux operating system, and low-voltage Intel Atom or VIA C7-M processors.

Pocket PC[edit]

An O2 pocket PC



Computer hardware is a comprehensive term for all physical and tangible parts of a computer, as distinguished from the data it contains or operates on, and the software that provides instructions for the hardware to accomplish tasks. Some sub-systems of a personal computer may contain processors that run a fixed program, or firmware, such as a keyboard controller. Firmware usually is not changed by the end user of the personal computer.




A peripheral is "a device connected to a computer to provide communication (such as input and output) or auxiliary functions (such as additional storage)".[49] Peripherals generally connect to the computer through the use of USB ports or inputs located on the I/O panel. USB Flash Drives provide portable storage using flash memory which allows users to access the files stored on the drive on any computer. Memory cards also provide portable storage for users, commonly used on other electronics such as mobile phones and digital cameras, the information stored on these cards can be accessed using a memory card reader to transfer data between devices. Webcams, which are either built into computer hardware or connected via USB are video cameras that records video in real time to either be saved to the computer or streamed somewhere else over the internet. Game controllers can be plugged in via USB and can be used as an input device for video games as an alternative to using keyboard and mouse. Headphones and speakers can be connected via USB or through an auxiliary port (found on I/O panel) and allow users to listen to audio accessed on their computer, however speakers may also require an additional power source to operate. Microphones can be connected through an audio input port on the I/O panel and allow the computer to convert sound into an electrical signal to be used or transmitted by the computer.


A screenshot of the LibreOffice Writer software


A screenshot of GIMP, which is a raster graphics editor.


Operating system[edit]



Early personal computers used operating systems that supported command line interaction, using an alphanumeric display and keyboard. The user had to remember a large range of commands to, for example, open a file for editing or to move text from one place to another. Starting in the early 1960s, the advantages of a graphical user interface began to be explored, but widespread adoption required lower cost graphical display equipment. By 1984, mass-market computer systems using graphical user interfaces were available; by the turn of the 21st century, text-mode operating systems were no longer a significant fraction of the personal computer market.[51]


Generally, a computer user uses application software to carry out a specific task.[52] System software supports applications[52] and provides common services such as memory management, network connectivity and device drivers, all of which may be used by applications but are not directly of interest to the end user. A simplified analogy in the world of hardware would be the relationship of an electric light bulb (an application) to an electric power generation plant (a system):[53] the power plant merely generates electricity, not itself of any real use until harnessed to an application like the electric light that performs a service that benefits the user.

Typical examples of software applications are word processors, spreadsheets, and media players. Multiple applications bundled together as a package are sometimes referred to as an application suite. Microsoft Office and LibreOffice,[54] which bundle together a word processor, a spreadsheet, and several other discrete applications, are typical examples.[55] The separate applications in a suite usually have a user interface that has some commonality making it easier for the user to learn and use each application. Often, they may have some capability to interact with each other in ways beneficial to the user; for example, a spreadsheet might be able to be embedded in a word processor document even though it had been created in the separate spreadsheet application.



PC gaming is popular among the high-end PC market. According to an April 2018 market analysis done by Newzoo, PC gaming has fallen behind both console and mobile gaming in terms of market share sitting at a 24% share of the entire market. The market for PC gaming still continues to grow and is expected to generate $32.3 billion in revenue in the year 2021.[56] PC gaming is at the forefront of competitive gaming, known as Esports with games such as ROBLOX and Minecraft leading the industry that is suspected to surpass a trillion dollars in revenue in 2019.[57]


Market share[edit]

Personal computers worldwide in million distinguished by developed and developing world


The global personal computer shipments were 350.9 million units in 2010,[61] 308.3 million units in 2009[62] and 302.2 million units in 2008.[63][64] The shipments were 264 million units in the year 2007, according to iSuppli,[65] up 11.2% from 239 million in 2006.[66] In 2004, the global shipments were 183 million units, an 11.6% increase over 2003.[67] In 2003, 152.6 million computers were shipped, at an estimated value of $175 billion.[68] In 2002, 136.7 million PCs were shipped, at an estimated value of $175 billion.[68] In 2000, 140.2 million personal computers were shipped, at an estimated value of $226 billion.[68] Worldwide shipments of personal computers surpassed the 100-million mark in 1999, growing to 113.5 million units from 93.3 million units in 1998.[69] In 1999, Asia had 14.1 million units shipped.[70]




In 2011, Deloitte consulting firm predicted that, smartphones and tablet computers as computing devices would surpass the PCs sales[76] (as has happened since 2012). As of 2013, worldwide sales of PCs had begun to fall as many consumers moved to tablets and smartphones. Sales of 90.3 million units in the 4th quarter of 2012 represented a 4.9% decline from sales in the 4th quarter of 2011.[77] Global PC sales fell sharply in the first quarter of 2013, according to IDC data. The 14% year-over-year decline was the largest on record since the firm began tracking in 1994, and double what analysts had been expecting.[78][79] The decline of Q2 2013 PC shipments marked the fifth straight quarter of falling sales.[80] "This is horrific news for PCs," remarked an analyst. "It's all about mobile computing now. We have definitely reached the tipping point."[78] Data from Gartner showed a similar decline for the same time period.[78] China's Lenovo Group bucked the general trend as strong sales to first time buyers in the developing world allowed the company's sales to stay flat overall.[78] Windows 8, which was designed to look similar to tablet/smartphone software, was cited as a contributing factor in the decline of new PC sales. "Unfortunately, it seems clear that the Windows 8 launch not only didn't provide a positive boost to the PC market, but appears to have slowed the market," said IDC Vice President Bob O’Donnell.[79]

In August 2013, Credit Suisse published research findings that attributed around 75% of the operating profit share of the PC industry to Microsoft (operating system) and Intel (semiconductors).[81] According to IDC, in 2013 PC shipments dropped by 9.8% as the greatest drop-ever in line with consumers trends to use mobile devices.[82]


Average selling price[edit]




Environmental impact[edit]

External costs of environmental impact are not fully included in the selling price of personal computers.[89]

Personal computers have become a large contributor to the 50 million tons of discarded electronic waste generated annually, according to the United Nations Environment Programme. To address the electronic waste issue affecting developing countries and the environment, extended producer responsibility (EPR) acts have been implemented in various countries and states.[90] In the absence of comprehensive national legislation or regulation on the export and import of electronic waste, the Silicon Valley Toxics Coalition and BAN (Basel Action Network) teamed up with electronic recyclers in the US and Canada to create an e-steward program for the orderly disposal of electronic waste. Some organizations oppose EPR regulation, and claim that manufacturers naturally move toward reduced material and energy use.

See also[edit]



  4. ^ The Encyclopedia of Human-Computer Interaction, 2nd Ed. End-User Development. Interaction Design Foundation. 2017.
  10. ^ Gene Carter, Wow! What a Ride!: A Quick Trip Through Early Semiconductor and Personal Computer Development, Lulu Press – 2016, chapter 8
  11. ^ "1959: Practical Monolithic Integrated Circuit Concept Patented | The Silicon Engine | Computer History Museum".
  12. ^ "1960: Metal Oxide Semiconductor (MOS) Transistor Demonstrated | The Silicon Engine | Computer History Museum".
  13. ^ "1964: First Commercial MOS IC Introduced | The Silicon Engine | Computer History Museum".
  14. ^ "1968: Silicon Gate Technology Developed for ICs | The Silicon Engine | Computer History Museum".
  15. ^ "1971: Microprocessor Integrates CPU Function onto a Single Chip | The Silicon Engine | Computer History Museum".
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  24. ^ Green, Wayne (February 1976). "Believe Me – I'm No Expert!". 73 Magazine. No. 184. Peterborough, NH: 73, Inc. p. 89. Wayne Green visited MITS in August 1975 and interviewed Ed Roberts. Article has several paragraphs on the design of the Altair 8800.
  25. ^ Garland, Harry (March 1977). "Design Innovations in Personal Computers". Computer. 10 (3): 24. doi:10.1109/c-m.1977.217669. There is little question that the current enthusiasm in personal computing was catalyzed by the introduction of the MITS Altair computer kit in January 1975.
  27. ^ Ceruzzi, Paul E. (2003). A History of Modern Computing. Cambridge, MA: MIT Press. p. 226. ISBN 978-0-262-53203-7. "This announcement [Altair 8800] ranks with IBM's announcement of the System/360 a decade earlier as one of the most significant in the history of computing."
  28. ^ Freiberger, Paul; Swaine, Michael (2000). Fire in the Valley: The Making of the Personal Computer. New York: McGraw-Hill. ISBN 978-0-07-135892-7.
  29. ^ What's New (February 1978), "Commodore Ships First PET Computers", BYTE, 3 (2): 190 Commodore press release. "The PET computer made its debut recently as the first 100 units were shipped to waiting customers in mid-October 1977."
  30. ^ "Apple II History". Apple II History. 2008-11-04. Retrieved May 8, 2014.
  31. ^ "Joe's Heathkit Computer Catalog Page". Retrieved 2019-03-07.
  32. ^ "Heathkit H8". Retrieved 2019-03-04.
  33. ^ "Heathkit H89 computer". Retrieved 2019-03-04.
  37. ^ "Computing Japan". Computing Japan. 54–59: 18. 1999. Retrieved February 6, 2012. ...its venerable PC 9800 series, which has sold more than 18 million units over the years, and is the reason why NEC has been the number one PC vendor in Japan for as long as anyone can remember.
  39. ^ "A Decade of Personal Computing". Information Week. August 5, 1991. p. 24.
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  41. ^ Ralston, Anthony; Reilly, Edwin (1993). "Workstation". Encyclopedia of Computer Science (Third ed.). New York: Van Nostrand Reinhold. ISBN 978-0-442-27679-9.
  43. ^ Scott Mueller, Upgrading and Repairing Laptops, Que Publishing, 2004, ISBN 0789728001, pp. 18–21
  44. ^ Desktop notebooks stake their claim, accessed October 19, 2007
  45. ^ Bott, Ed. "The PC was supposed to die a decade ago. Instead, this happened". ZDNet.
  46. ^ Erica Ogg (August 20, 2009). "Time to drop the Netbook label". CNN.
  49. ^ "Definition of PERIPHERAL". Retrieved 2019-03-05.
  51. ^ "GUI Definition". Retrieved 2019-02-22.
  52. ^ a b Weik, Martin (2000). Computer Science and Communications Dictionary. Boston, MA: Springer. ISBN 978-0-7923-8425-0.
  54. ^ Kinser, Jason (2015). Kinematic Labs with Mobile Devices. Kinematic Labs with Mobile Devices. Morgan and Claypool. doi:10.1088/978-1-6270-5628-1. ISBN 978-1-6270-5627-4.
  56. ^ "Global Games Market Revenues 2018 | Per Region & Segment". Newzoo. Retrieved 2019-04-25.
  57. ^ "Newzoo: Global esports market will exceed $1 billion in 2019". Retrieved 2019-04-25.
  65. ^ ISuppli Raises 2007 Computer Sales Forecast,, 2007-06-19, retrieved January 13, 2009
  67. ^ Global PC Sales Leveling Off,, archived from the original on June 14, 2011, retrieved January 13, 2009
  72. ^ "Gartner Says More than 1 Billion PCs in Use Worldwide and Headed to 2 Billion Units by 2014" (Press release). Gartner. June 23, 2008. Retrieved 2010-10-14.
  76. ^ Tablets, smartphones to outsell PCs
  89. ^ Mattison, Richard (2012-10-03). "The true cost of personal computers". GreenBiz. GreenBiz Group Inc. Retrieved 28 September 2016.
  90. ^ Nash, Jennifer; Bosso, Christopher (2013). "Extended Producer Responsibility in the United States: Full Speed Ahead?" (PDF). Journal of Industrial Ecology. 17 (2 – RPP–2013–04): 175–185. doi:10.1111/j.1530-9290.2012.00572.x. Retrieved August 23, 2014.

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