A personal computer (PC) is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator. PCs include any type of computer that is used in a "personal" manner. This is in contrast to the batch processing or time-sharing models which allowed large expensive mainframe systems to be used by many people, usually at the same time, or large data processing systems which required a full-time staff to operate efficiently. It is also in contrast with the more recent trend of controlling software availability through an intervening third party such as the Apple App Store.

A personal computer may be a desktop computer, a laptop, a tablet PC, or a handheld PC (also called a palmtop). The most common microprocessors in personal computers are x86-compatible CPUs. Software applications for personal computers include word processing, spreadsheets, databases, Web browsers and e-mail clients, games, and myriad personal productivity and special-purpose software applications. Modern personal computers often have connections to the Internet, allowing access to the World Wide Web and a wide range of other resources.

A PC may be used at home or in an office. Personal computers may be connected to a local area network (LAN), either by a cable or a wireless connection.

While early PC owners usually had to write their own programs to do anything useful with the machines, today’s users have access to a wide range of commercial and non-commercial software, which is provided in ready-to-run or ready-to-compile form. Since the 1980s, Microsoft and Intel have dominated much of the personal computer market, first with MS-DOS and then with the Wintel platform.

An illustration of a modern desktop computer

In what was later to be called The Mother of All Demos, SRI researcher Douglas Englebart in 1968 gave a preview of what would become the staples of daily working life in the 21st century - 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.

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.

HP 9830 was an early desktop computer with printer

In the 1970s Hewlett Packard introduced fully BASIC programmable computers that fit entirely on top of a desk, including a keyboard, a small one-line display and printer. The Wang 2200 of 1973 had a full-size CRT and cassette tape storage. The IBM 5100 in 1975 had a small CRT display and could be programmed in BASIC and APL. These were generally expensive specialized computers sold for business or scientific uses. The introduction of the microprocessor, a single chip with all the circuitry that formerly occupied large cabinets, led to the proliferation of personal computers after 1975.

Early personal computers - generally called microcomputers - were sold often in kit form and in limited volumes, and were of interest mostly to hobbyists and technicians. Minimal programming was done with toggle switches to enter instructions, and output was provided by front panel lamps. Practical use required peripherals such as keyboards, computer terminals, disk drives, and printers. Micral N was the earliest commercial, non-kit microcomputer based on a microprocessor, the Intel 8008. It was built starting in 1972 and about 90,000 units were sold. The first true Personal Computer was the Sphere 1 computer, created in Bountiful, Utah in 1975 by computer pioneer Michael D. Wise (1949–2002). At first, Sphere 1 was sold as a kit, but was later sold as fully assembled PC. The Sphere 1 qualified as The First Personal Computer because it included a keyboard, a number pad, and a monitor. In 1976 Steve Jobs and Steve Wozniak sold the Apple I computer circuit board, which was fully prepared and contained about 30 chips. The first successfully mass marketed personal computer was the Commodore PET introduced in January 1977, which bore a striking resemblance to Sphere 1 of two years earlier. It was soon followed by the TRS-80 from Radio Shack and the popular Apple II. Mass-market ready-assembled computers allowed a wider range of people to use computers, focusing more on software applications and less on development of the processor hardware.

Through the late 1970s and into the 1980s, computers were developed for household use, with software for personal productivity, programming and games. One such machine, the Commodore 64, totaled 17 million units sold, making it the best-selling single personal computer model of all time. Somewhat larger and more expensive systems (although still low-cost compared with minicomputers and mainframes) were aimed at office and small business use. Workstations are characterized by high-performance processors and graphics displays, with large local disk storage, networking capability, and running under a multitasking operating system.

IBM 5150 as of 1981

Eventually due to the influence of the IBM-PC on the personal computer market, personal computers and home computers lost any technical distinction. Business computers acquired color graphics capability and sound, and home computers and game systems users used the same processors and operating systems as office workers. Mass-market computers had graphics capabilities and memory comparable to dedicated workstations of a few years before. Even local area networking, originally a way to allow business computers to share expensive mass storage and peripherals, became a standard feature of personal computers used at home.

In 1982 "The Computer" was named Machine of the Year by Time Magazine
Workstation

Dell OptiPlex desktop computer

A laptop computer or simply laptop, also called a notebook computer or sometimes a notebook, is a small personal computer designed for portability. Usually all of the interface hardware needed to operate the laptop, such as USB ports (previously parallel and serial ports), graphics card, sound channel, etc., are built in to a single unit. Laptops contain high capacity batteries that can power the device for extensive periods of time, enhancing portability. Once the battery charge is depleted, it will have to be recharged through a power outlet. In the interest of saving power, weight and space, they usually share RAM with the video channel, slowing their performance compared to an equivalent desktop machine.

Acer 8920 Gemstone Laptop.

 

An HP netbook

A tablet PC is a notebook or slate-shaped mobile computer, first introduced by Pen computing in the early 90s with their PenGo Tablet Computer and popularized by Microsoft. Its touchscreen or graphics tablet/screen hybrid technology allows the user to operate the computer with a stylus or digital pen, or a fingertip, instead of a keyboard or mouse. The form factor offers a more mobile way to interact with a computer. Tablet PCs are often used where normal notebooks are impractical or unwieldy, or do not provide the needed functionality.

As technology and functionality continue to progress, prototype tablet computers will continue to emerge. The Microsoft Courier, a personal business device, has two 7" monitors that support multi-touch gestures, Wi-Fi capabilities and has a built-in camera. The device looks to be a replacement to traditional planners while offering what most digital planners cannot, two pages and large writing spaces. This particular device, however, has been recently abandoned and the market is currently being led by the popular iPad from Apple Inc.

HP Compaq tablet PC with rotating/removable keyboard.

The ultra-mobile PC (UMPC) is a specification for a small form factor of tablet PCs. It was developed as a joint development exercise 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

Samsung Q1 Ultra-Mobile PC.

A pocket PC is a hardware specification for a handheld-sized computer (personal digital assistant) that runs the Microsoft Windows Mobile operating system. It may have the capability to run an alternative operating system like NetBSD or Linux. It has many of the capabilities of modern desktop PCs.

Currently there are tens of thousands of applications for handhelds adhering to the Microsoft Pocket PC specification, many of which are freeware. Some of these devices also include mobile phone features. Microsoft compliant Pocket PCs can also be used with many other add-ons like GPS receivers, barcode readers, RFID readers, and cameras. In 2007, with the release of Windows Mobile 6, Microsoft dropped the name Pocket PC in favor of a new naming scheme. Devices without an integrated phone are called Windows Mobile Classic instead of Pocket PC. Devices with an integrated phone and a touch screen are called Windows Mobile Professional

An O pocket PC