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This article is about personal computers in general. For computers generally referred to as "PCs", see IBM PC compatible. For hardware components dealing with personal computers, see Personal computer hardware      (Dell XPS M1210 Battery)          .

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. 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         (Dell Studio XPS 1340 Battery)          .

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        (Dell Studio XPS 1640 Battery)       .

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      (Dell Vostro 1710 Battery)        .

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       (ASUS EEE PC900 battery) .

History

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Main article: History of personal computers   (Dell RM791 battery)

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        (Sony VGP-BPS13 battery)      .

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      (sony vgp-bpl9 battery)

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         (Sony VGP-BPL11 battery)     .

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        (Sony VGP-BPL15 battery)         .

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          (Dell Inspiron E1505 battery )        .

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         (Dell Latitude E6400 battery)         .

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 pre-assembled computers allowed a wider range of people to use computers, focusing more on software applications and less on development of the processor hardware       (HP Pavilion dv6000 Battery)        .

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       (Hp Pavilion dv3-1000 battery)       .

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        (Dell Precision M70 Battery)        .

In 1984, Dr. Mark Dean created a device called the ISA systems bus, which allows a personal computer to have several machines connected to it at once, such as a printer and scanner or modem. ISA is widely used today and Dean also received the Black Engineer of the Year President’s Award in 1997 for his contribution . However, card slots already existed before the ISA bus of the IBM-PC in the Apple         (Acer Aspire One battery)         .

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        (Toshiba Satellite L305 Battery)        .

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.

Market and sales

See also: Market share of leading PC vendors

Personal computers worldwide in million distinguished by developed and developing world    (Toshiba Satellite Pro M15 Battery)

In 2001, 125 million personal computers were shipped in comparison to 48 thousand in 1977. More than 500 million personal computers were in use in 2002 and one billion personal computers had been sold worldwide from the mid-1970s up to this time. Of the latter figure, 75 percent were professional or work related, while the rest were sold for personal or home use. About 81.5 percent of personal computers shipped had been desktop computers, 16.4 percent laptops and 2.1 percent servers       (Toshiba Satellite M65 battery)          .

The United States had received 38.8 percent (394 million) of the computers shipped, Europe 25 percent and 11.7 percent had gone to the Asia-Pacific region, the fastest-growing market as of 2002. The second billion was expected to be sold by 2008. Almost half of all the households in Western Europe had a personal computer and a computer could be found in 40 percent of homes in United Kingdom, compared with only 13 percent in 1985         (Toshiba Satellite T4900 Battery)        .

The global personal computer shipments were 264 million units in the year 2007, according to iSuppli,  up 11.2 percent from 239 million in 2006.  In 2004, the global shipments were 183 million units, an 11.6 percent increase over 2003. In 2003, 152.6 million computers were shipped, at an estimated value of $175 billion. In 2002, 136.7 million PCs were shipped, at an estimated value of $175 billion     (Toshiba PA3399U-2BRS battery)        .

In 2000, 140.2 million personal computers were shipped, at an estimated value of $226 billion.  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.  In 1999, Asia had 14.1 million units shipped        (Toshiba Satellite A200 Battery)       .

As of June 2008, the number of personal computers in use worldwide hit one billion, while another billion is expected to be reached by 2014. Mature markets like the United States, Western Europe and Japan accounted for 58 percent of the worldwide installed PCs. The emerging markets were expected to double their installed PCs by 2012 and to take 70 percent of the second billion PCs. About 180 million computers (16 percent of the existing installed base) were expected to be replaced and 35 million to be dumped into landfill in 2008. The whole installed base grew 12 percent annually      (Toshiba Satellite 1200 Battery)       .

In the developed world, there has been a vendor tradition to keep adding functions to maintain high prices of personal computers. However, since the introduction of the One Laptop per Child foundation and its low-cost XO-1 laptop, the computing industry started to pursue the price too. Although introduced only one year earlier, there were 14 million netbooks sold in 2008     (Toshiba NB100 Battery).

Besides the regular computer manufacturers, companies making especially rugged versions of computers have sprung up, offering alternatives for people operating their machines in extreme weather or environments.

Average selling price

For Microsoft Windows systems, the average selling price (ASP) showed a decline in 2008/2009, possibly due to low-cost netbooks, drawing $569 for desktop computers and $689 for laptops at U.S. retail in August 2008. In 2009, ASP had further fallen to $533 for desktops and to $602 for notebooks by January and to $540 and $560 in February       (Toshiba Satellite M300 Battery)         .

According to research firm NPD, the average selling price of all Windows portable PCs has fallen from $659 in October 2008 to $519 in October 2009.

Types

Workstation

Sun SPARCstation 1+, 25 MHz RISC processor from early 1990s

Main article: Workstation       (Dell INSPIRON 1525 battery)

A workstation is a high-end personal computer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems. Workstations are used for tasks such as computer-aided design, drafting and modelling, computation-intensive scientific and engineering calculations, image processing, architectural modelling, and computer graphics for animation and motion picture visual effects      (SONY VAIO VGN-FZ280E Battery)        .

Desktop computer

Main article: Desktop computer

Dell OptiPlex desktop computer

Prior to the wide spread of PCs a computer that could fit on a desk was considered remarkably small. Today the phrase usually indicates a particular style of computer case          (SONY VAIO VGN-FZ410 Battery)      .

Desktop computers come in a variety of styles ranging from large vertical tower cases to small form factor models that can be tucked behind an LCD monitor. In this sense, the term 'desktop' refers specifically to a horizontally-oriented case, usually intended to have the display screen placed on top to save space on the desk top. Most modern desktop computers have separate screens and keyboards       (SONY VAIO VGN-FZ160 Battery)         .

Single unit

Single unit PCs (also known as all-in-one PCs) are a subtype of desktop computers, which combine the monitor and case of the computer within a single unit. The monitor often utilizes a touchscreen as an optional method of user input, however detached keyboards and mice are normally still included. The inner components of the PC are often located directly behind the monitor, and many are built similarly to laptops       (SONY VAIO VGN-FZ38M Battery)       .

Nettop

Main article: Nettop

A subtype of desktops, called nettops, was introduced by Intel in February 2008 to describe low-cost, lean-function, desktop computers. A similar subtype of laptops (or notebooks) are the netbooks (see below). These feature the new Intel Atom processor which specially enables them to consume less power and to be built into small enclosures         (SONY VAIO VGN-FZ21m Battery)  .

Laptop

Main article: Laptop

Acer 8920 Gemstone Laptop.

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        (SONY VAIO VGN-FZ18m Battery)      .

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     (SONY VAIO VGN-FZ11m Battery)         .

One main drawback of the laptop is sometimes, due to the size and configuration of components, relatively little can be done to upgrade the overall computer from its original design. Internal upgrades are either not manufacturer recommended, can damage the laptop if done with poor care or knowledge, or in some cases impossible, making the desktop PC more modular. Some internal upgrades, such as memory and hard disks upgrades are often easy, a display or keyboard upgrade is usually impossible        (SONY VAIO VGN-FZ11z Battery)          .

The laptop has the same access as the desktop to the wide variety of devices, such as external displays, mice, cameras, storage devices and keyboards, which may be attached externally through USB ports and other less common ports such as external video.

A subtype of notebooks, called subnotebooks, are computers with most of the features of a standard laptop computer but smaller          (SONY VAIO VGN-FZ11l Battery)      .

They are larger than hand-held computers, and usually run full versions of desktop/laptop operating systems. Ultra-Mobile PCs (UMPC) are usually considered subnotebooks, or more specifically, subnotebook Tablet PCs (see below). Netbooks are sometimes considered in this category, though they are sometimes separated in a category of their own (see below).

Desktop replacements, meanwhile, are large laptops meant to replace a desktop computer while keeping the mobility of a laptop. Entertainment laptops emphasize large, HDTV-resolution screens and video processing capabilities     (SONY VAIO VGN-FZ31z Battery)        .

Netbook

Main article: Netbook

An HP netbook

Netbooks (also called mini notebooks or subnotebooks) are a rapidly evolving category of small, light and inexpensive laptop computers suited for general computing and accessing web-based applications; they are often marketed as "companion devices," that is, to augment a user's other computer access    (Dell Studio 1555 Battery)       .

Walt Mossberg called them a "relatively new category of small, light, minimalist and cheap laptops."  By August 2009, CNET called netbooks "nothing more than smaller, cheaper notebooks."

At their inception in late 2007 — as smaller notebooks optimized for low weight and low cost— netbooks omitted key features (e.g., the optical drive), featured smaller screens and keyboards, and offered reduced specification and computing power    (Dell Vostro 1720 Battery)        .

Over the course of their evolution, netbooks have ranged in size from below 5 in to over 13 in, and from ~1 kg (2-3 pounds). Often significantly less expensive than other laptops,by mid-2009, netbooks had been offered to users "free of charge", with an extended service contract purchase of a cellular data plan      (Dell Vostro 1500 Battery)       .

In the short period since their appearance, netbooks have grown in size and features, now converging with new smaller, lighter notebooks. By mid 2009, CNET noted "the specs are so similar that the average shopper would likely be confused as to why one is better than the other," noting "the only conclusion is that there really is no distinction between the devices      (Dell Latitude D830 Battery)        ."

Tablet PC

Main article: Tablet PC

HP Compaq tablet PC with rotating/removable keyboard.

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      (Dell Latitude D620 Battery)      .

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         (SONY VAIO VGN-FZ150E Battery)         .

As technology and functionality continue to progress, prototype tablet PCs 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         (Dell Studio 1735 Battery)       .

Ultra-Mobile PC

Main article: Ultra-Mobile PC

Samsung Q1 Ultra-Mobile PC.

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        (Dell Inspiron 300M Battery)    .

Home theater PC

Main article: Home theater PC

Antec Fusion V2 home theater PC with keyboard on top.

A home theater PC (HTPC) is a convergence device that combines the functions of a personal computer and a digital video recorder. It is connected to a television or a television-sized computer display and is often used as a digital photo, music, video player, TV receiver and digital video recorder      (Dell Studio 1737 battery)       .

Home theater PCs are also referred to as media center systems or media servers. The general goal in a HTPC is usually to combine many or all components of a home theater setup into one box. They can be purchased pre-configured with the required hardware and software needed to add television programming to the PC, or can be cobbled together out of discrete components as is commonly done with MythTV, Windows Media Center, GB-PVR, SageTV, Famulent or LinuxMCE      (Dell XPS M1530 battery)      .

Pocket PC

Main article: Pocket PC

An O2 pocket 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       (Dell XPS M2010 battery)          .

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       (Dell Vostro 1000 battery)       .

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.

Motherboard

The motherboard, also referred to as systemboard or mainboard, is the primary circuit board within a personal computer. Many other components connect directly or indirectly to the motherboard        (HP Pavilion dv9000 battery)         .

Motherboards usually contain one or more CPUs, supporting circuitry - usually integrated circuits (ICs) - providing the interface between the CPU memory and input/output peripheral circuits, main memory, and facilities for initial setup of the computer immediately after power-on (often called boot firmware or, in IBM PC compatible computers, a BIOS). In many portable and embedded personal computers, the motherboard houses nearly all of the PC's core components       (Hp 520 battery)       .

Often a motherboard will also contain one or more peripheral buses and physical connectors for expansion purposes. Sometimes a secondary daughter board is connected to the motherboard to provide further expandability or to satisfy space constraints.

Main memory

Main article: Primary storage

A PC's main memory is fast storage that is directly accessible by the CPU, and is used to store the currently executing program and immediately needed data. PCs use semiconductor random access memory (RAM) of various kinds such as DRAM, SDRAM or SRAM as their primary storage       (SONY VGP-BPS13 Battery)      .

Which exact kind depends on cost/performance issues at any particular time. Main memory is much faster than mass storage devices like hard disks or optical discs, but is usually volatile, meaning it does not retain its contents (instructions or data) in the absence of power, and is much more expensive for a given capacity than is most mass storage. Main memory is generally not suitable for long-term or archival data storage     (SONY VAIO VGN-FZ Battery)   .

Hard disk

Main article: Hard disk drive

A Western Digital 250 GB hard disk drive.

Mass storage devices store programs and data even when the power is off; they do require power to perform read and write functions during usage. Although flash memory has dropped in cost, the prevailing form of mass storage in personal computers is still the hard disk       (Dell RM791 battery)        .

The disk drives use a sealed head/disk assembly (HDA) which was first introduced by IBM's "Winchester" disk system. The use of a sealed assembly allowed the use of positive air pressure to drive out particles from the surface of the disk, which improves reliability.

If the mass storage controller provides for expandability, a PC may also be upgraded by the addition of extra hard disk or optical disc drives. For example, BD-ROMs, DVD-RWs, and various optical disc recorders may all be added by the user to certain PCs     (Toshiba Portege R200 Battery) .

Standard internal storage device connection interfaces are PATA, Serial ATA, SCSI

Video card

Main article: Video card

ATI Radeon video card

The video card - otherwise called a graphics card, graphics adapter or video adapter - processes and renders the graphics output from the computer to the computer display, and is an essential part of the modern computer. On older models, and today on budget models, graphics circuitry tended to be integrated with the motherboard but, for modern flexible machines, they are supplied in PCI, AGP, or PCI Express format        (Toshiba Satellite M60 battery)          .

When the IBM PC was introduced, most existing business-oriented personal computers used text-only display adapters and had no graphics capability. Home computers at that time had graphics compatible with television signals, but with low resolution by modern standards owing to the limited memory available to the eight-bit processors available at the time      (Dell Studio 1555 Battery)      .

Visual display unit

Main article: Visual display unit

A flat-panel LCD monitor.

A visual display unit (or monitor) is a piece of electrical equipment, usually separate from the computer case, which displays viewable images generated by a computer without producing a permanent record      (Dell Vostro 1400 Battery)         .

The word "monitor" is used in other contexts; in particular in television broadcasting, where a television picture is displayed to a high standard. A computer display device is usually either a cathode ray tube or some form of flat panel such as a TFT LCD. The monitor comprises the display device, circuitry to generate a picture from electronic signals sent by the computer, and an enclosure or case  (Dell Vostro 1500 Battery)      .

Within the computer, either as an integral part or a plugged-in Expansion card, there is circuitry to convert internal data to a format compatible with a monitor. The images from monitors originally contained only text, but as Graphical user interfaces emerged and became common, they began to display more images and multimedia content     (Toshiba Satellite Pro M50 Battery)     .

Keyboard

Main article: Keyboard (computing)

A computer keyboard

In computing, a keyboard is an arrangement of buttons that each correspond to a function, letter, or number. They are the primary devices of inputing text. In most cases, they contain an array of keys specifically organized with the corresponding letters, numbers, and functions printed or engraved on the button      (Dell Vostro 1510 Battery)        .

They are generally designed around an operators language, and many different versions for different languages exist. In English, the most common layout is the QWERTY layout, which was originally used in typewriters. They have evolved over time, and have been modified for use in computers with the addition of function keys, number keys, arrow keys, and OS specific keys       (Dell Latitude XT2 Tablet PC Battery)       .

Often, specific functions can be achieved by pressing multiple keys at once or in succession, such as inputing characters with accents or opening a task manager. Programs use keyboard shotcuts very differently and all use different keyboard shortcuts for different program specific operations, such as refreshing a web page in a web browser or selecting all text in a word processor     (Dell Vostro A90 Battery)          .

Mouse

Main article: Mouse (computing)

Apple Mighty Mouse that detects the right and left clicks through what appears to be one large button.

A Mouse on a computer is a small, slidable device that users hold and slide around to point at, click on, and sometimes drag objects on screen in a graphical user interface using a pointer on screen. Almost all Personal Computers have mice        ( HP Pavilion DV7 Battery)         .

It may be plugged into a computer's rear mouse socket, or as a USB device, or, more recently, may be connected wirelessly via a USB antenna or Bluetooth antenna. In the past, they had a single button that users could press down on the device to "click" on whatever the pointer on the screen was hovering over          ( HP Pavilion DV7 Battery)      .

Now, however, many Mice have two or three buttons(possibly more); a "right click" function button on the mouse, which performs a secondary action on a selected object, and a scroll wheel, which users can rotate using their fingers to "scroll" up or down. The scroll wheel can also be pressed down, and therefore be used as a third button. Some mouse wheels may be tilted from side to side to allow sideways scrolling. Different programs make use of these functions differently, and may scroll horizontally by default with the scroll wheel, open different menus with different buttons, among others. These functions may be user defined through software utilities   (Toshiba Satellite Pro M10 Battery)        .

Mice traditionally detected movement and communicated with the computer with an internal "mouse ball"; and used optical encoders to detect rotation of the ball and tell the computer where the mouse has moved. However, these systems were subject to low durability, accuracy and required internal cleaning. Modern mice use optical technology to directly trace movement of the surface under the mouse and are much more accurate, durable and almost maintenace free. They work on a wider variety of surfaces and can even operate on walls, ceilings or other non-horizontal surfaces      (Dell Inspiron 300M Battery)      .

The iPad is a tablet computer designed and developed by Apple. It is particularly marketed as a platform for audio and visual media such as books, periodicals, movies, music, and games, as well as web content. At about 700 grams (25 ounces), its size and weight are between those of most contemporary smartphones and laptop computers. Apple released the iPad in April 2010, and sold 3 million of the devices in 80 days         (Dell XPS M1210 Battery)         .

The iPad runs the same operating system as the earlier iPod Touch and iPhone, albeit a slightly older version. It can run its own applications as well as ones developed for the iPhone. Without modification, it will only run programs approved by Apple and distributed via its online store       (Dell Studio XPS 1340 Battery)         .

Like iPhone and iPod Touch, the iPad is controlled by a multitouch display — a break from most previous tablet computers, which used a pressure-triggered stylus. The iPad uses a Wi-Fi data connection to browse the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection. The device is managed and synced by iTunes on a personal computer via USB cable       (Dell Studio XPS 1640 Battery)        .

Media reaction to the device has generally been neutral or positive, with more positive reaction after the device was launched.

History

Apple's first tablet computer was the Newton MessagePad 100,  introduced in 1993, which led to the creation of the ARM6 processor core with Acorn Computers. Apple also developed a prototype PowerBook Duo-based tablet, the PenLite, but in order to avoid hurting MessagePad sales did not sell it.  Apple released several more Newton-based PDAs, and discontinued the last, the MessagePad 2100, in 1998     (Dell Vostro 1710 Battery)       .

With the success of the introduction of portable music player iPod in 2001, Apple re-entered the mobile-computing market in 2007 with the iPhone. Smaller than the iPad but featuring a camera and mobile phone, it pioneered the multitouch finger-sensitive touchscreen interface of Apple's mobile operating system—iOS. By late 2009, the iPad's release had been rumored for several years. Mostly referred to as "Apple's tablet", iTablet and iSlate were among the speculated names        (ASUS EEE PC900 battery)       .

The iPad was announced on January 27, 2010 by Steve Jobs at an Apple press conference at the Yerba Buena Center for the Arts in San Francisco.

Jobs later admitted that the iPad was developed before the iPhone. Upon realizing that it would work just as well as a mobile phone, Jobs put development of the iPad on hold and decided to develop the iPhone instead      (Dell RM791 battery)      .

Hardware

Screen and input

The iPad's touchscreen display is a 25 cm (9.7 in) liquid crystal display (1024 × 768 pixels) with fingerprint-resistant and scratch-resistant glass. Like the iPhone, the iPad is designed to be controlled by bare fingers; normal gloves and styli that prevent electrical conductivity may not be used,  although there are special gloves and styli designed for this use     (Sony VGP-BPS13 battery)         .

The display responds to two other sensors: an ambient light sensor to adjust screen brightness and a 3-axis accelerometer to sense iPad orientation and switch between portrait and landscape modes. Unlike the iPhone and iPod touch built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad built-in applications support screen rotation in all four orientations (the three aforementioned ones along with upside-down), meaning that the device has no intrinsic "native" orientation; only the relative position of the home button changes      (sony vgp-bpl9 battery)      .

The iPad has a switch to lock out the screen rotation function (reportedly to prevent unintended rotation when the user is lying down).  There are a total of four physical switches, including a home button below the display that returns the user to the main menu, and three plastic physical switches on the sides: wake/sleep and volume up/down, along with the screen rotation lock.

Ars Technica noted the similarity between the iPad and Star Trek's fictional PADD tablet computer, both in name and functionality        (Sony VGP-BPL11 battery)       .

Connectivity

Steve Jobs, Apple CEO, introducing the iPad

The iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Maps. The 3G model contains A-GPS to allow its position to be calculated with GPS or relative to nearby cellphone towers; it also has a black plastic accent on the back side to improve 3G radio sensitivity        (Sony VGP-BPL15 battery)         .

For wired connectivity, the iPad has a dock connector; it lacks the Ethernet and USB ports of larger computers.

Audio and output

Back of the iPad

The iPad has two internal speakers that push mono sound through two small sealed channels to the three audio ports carved into the bottom-right of the unit. A volume switch is on the right side of the unit    (Dell Inspiron E1505 battery )      .

A 3.5-mm TRS connector audio-out jack on the top-left corner of the device provides stereo sound for headphones with or without microphones and/or volume controls. The iPad also contains a microphone that can be used for voice recording.

The built-in Bluetooth 2.1 + EDR interface allows wireless headphones and keyboards to be used with the iPad. However, the iOS does not currently support file transfer via Bluetooth. iPad also features 1024 x 768 VGA video output for connecting an external display or television      (Dell Latitude E6400 battery)        .

Power and battery

iPad in the iPad Keyboard Dock

The iPad uses an internal rechargeable lithium-ion polymer battery. The batteries are made in Taiwan by Simplo Technology, which makes 60% of them, and Dynapack International Technology. The iPad is designed to be charged with a high current (2 amperes) using the included USB 10 W power adapter. While it can be charged by a standard USB port from a computer, these are limited to 500 milliamperes (half an amp)       (HP Pavilion dv6000 Battery)       .

As a result, if the iPad is turned on while being charged with a normal USB computer port, it will charge much more slowly, if at all.

Apple claims that the iPad's battery can provide up to 10 hours of video, 140 hours of audio playback, or one month on standby. Like any battery technology, the iPad's LiPo battery loses capacity over time, but is not designed to be user-replaceable. In a program similar to the battery-replacement program for the iPod and the original iPhone, Apple will replace an iPad that does not hold an electrical charge with a refurbished iPad for a fee of US$99 (plus $6.95 shipping)        (Hp Pavilion dv3-1000 battery)      .

Storage and SIM

The iPad was released with three options for internal storage size: a 16, 32, or 64 GB flash drive. All data is stored on the flash drive and there is no option to expand storage. Apple sells a camera connection kit with an SD card reader, but it can only be used to transfer photos and videos     (Dell Precision M70 Battery)         .

The side of the Wi-Fi + 3G model has a micro-SIM slot (not mini-SIM). Unlike the iPhone, which is usually sold locked to specific carriers, the 3G iPad is sold unlocked and can be used with any compatible GSM carrier.  Japan is the exception to this, where the iPad 3G is locked to Softbank. In the U.S., data network access via T-Mobile's network is limited to slower EDGE cellular speeds because T-Mobile's 3G Network uses different frequencies        (Acer Aspire One battery)    .

Optional accessories

The iPad in its case

Apple offers several iPad accessories, including:

iPad Keyboard Dock with hardware keyboard, 30-pin connector, and audio jack

iPad Case which can be used to stand the iPad in various positions

iPad Dock with 30-pin connector and audio jack    (Hp 520 battery)

iPad Dock Connector to VGA Adapter for external monitor or projector

iPad Camera Connection Kit including a USB Type A connector adapter and an SD card reader, for transferring photos and videos

iPad 10W USB Power Adapter with 2 A output (10 W)       (Toshiba Satellite L305 Battery)

Technical specifications

Model       Wi-Fi         Wi-Fi + 3G

Announcement date        January 27, 2010

Release date   April 3, 2010         April 30, 2010

Display     9.7 inches (25 cm) multitouch display at a resolution of 1024 × 768 pixels with LED backlighting and a fingerprint and scratch resistant coating        (Toshiba Satellite Pro M15 Battery)          .

Processor         1 GHz Apple A4 System on a chip

Storage    Fixed capacity of 16, 32, or 64 GB

Wireless  Wi-Fi (802.11a/b/g/n), Bluetooth 2.1+EDR

No wireless wide-area network interface       3G cellular HSDPA, 2G cellular EDGE

Geolocation     Skyhook Wireless     Assisted GPS, Skyhook Wireless, cellular network

Environmental sensors    Accelerometer, ambient light sensor, magnetometer (for digital compass)

Operating system    iOS 3.2.2 and iOS 4.2 Due November         (Toshiba Satellite M65 battery)

Battery    Built-in lithium-ion polymer battery; (10 hours video,  140 hours audio,  1 month standby )

Weight     680 g (1.5 lb)         730 g (1.6 lb)

Dimensions      242.8 × 189.7 × 13.4 mm (9.56 × 7.47 × 0.53 in)

Mechanical keys      Home, sleep, screen rotation lock (mute switch on iOS4.2, volume       (Toshiba Satellite T4900 Battery)      .

Manufacture

The iPad is assembled by Foxconn, which also manufactures Apple's iPod, iPhone and Mac Mini, in its largest plant in Shenzhen, China.

iSuppli estimated that each iPad 16 GB Wi-Fi version costs Apple US$259.60 to manufacture, a total that excludes research, development, licensing and patent costs. Apple does not disclose the makers of iPad components, but teardown reports and analysis from industry insiders indicate that various parts and their suppliers include       (Toshiba PA3399U-2BRS battery)      :

Apple A4 SoC: Samsung..

NAND flash RAM chips: Toshiba; except Samsung for the 64 GB model..

Touch-screen chips: Broadcom.

Touch panels: Wintek. (Got the job after TPK Touch Solutions was unable to fulfill its orders, delaying the iPad's release from late March to early April. )

Case: Catcher Technologies      (Toshiba Satellite A200 Battery)         .

LCD drivers: Novatek Microelectronics.

Batteries: 60% are made in Taiwan by Simplo Technology, 40% by Dynapack International.

Accelerometer: STMicroelectronics.

Software

Like the iPhone, with which it shares a development environment (iPhone SDK, or software development kit, version 3.2 onwards), the iPad only runs its own software, software downloaded from Apple's App Store, and software written by developers who have paid for a developer's license on registered devices.  The iPad runs almost all third-party iPhone applications, displaying them at iPhone size or enlarging them to fill the iPad's screen       (Toshiba Satellite 1200 Battery)       .

Developers may also create or modify apps to take advantage of the iPad's features. Application developers use iPhone SDK for developing applications for iPad. The iPad has been shipping with a customized iPad-only version of iPhone OS, dubbed v3.2. On September 1, it was announced the iPad will get iOS 4.2 by November 2010      (Toshiba NB100 Battery)       .

Applications

The iPad comes with several applications, including Safari, Mail, Photos, Video, YouTube, iPod, iTunes, App Store, iBooks, Maps, Notes, Calendar, Contacts, and Spotlight Search.  Several are improved versions of applications developed for the iPhone.

The iPad syncs with iTunes on a Mac or Windows PC.  Apple ported its iWork suite from the Mac to the iPad, and sells pared down versions of Pages, Numbers, and Keynote apps in the App Store       (Toshiba Satellite M300 Battery)        .

Although the iPad is not designed to replace a mobile phone, a user can use a wired headset or the built-in speaker and microphone and place phone calls over Wi-Fi or 3G using a VoIP application.  The iPad has lots of third party applications available for it; as of September 1, 2010 there were 25000 iPad specific apps on the AppStore         (Dell INSPIRON 1525 battery)      .

Digital rights management

For more details on the digital rights management, see iOS.

The iPad employs DRM intended to lock purchased content - including TV shows, movies, and apps-- to operate only on Apple's platform. Also, the iPad's development model requires anyone creating an app for the iPad to sign a non-disclosure agreement and pay for a developer subscription. Furthermore, critics argue Apple's centralized app approval process and control and lockdown of the platform itself could stifle software innovation       (SONY VAIO VGN-FZ280E Battery)       .

Of particular concern to digital rights advocates is the ability for Apple to remotely disable or delete apps, media, or data on the iPad at will.

Digital rights advocates, including the Free Software Foundation, Electronic Frontier Foundation, and computer engineer and activist Brewster Kahle, have criticized the iPad for its digital rights restrictions. Paul Sweeting, an analyst with GigaOM, is quoted by National Public Radio saying, "With the iPad, you have the anti-Internet in your hands       (SONY VAIO VGN-FZ410 Battery)      .

It offers [the major media companies] the opportunity to essentially re-create the old business model, wherein they are pushing content to you on their terms rather than you going out and finding content, or a search engine discovering content for you." But Sweeting also thinks Apple's limitations make its products feel like living in a safe neighborhood, saying, "Apple is offering you a gated community where there's a guard at the gate, and there's probably maid service, too        (SONY VAIO VGN-FZ160 Battery)       ."

Laura Sydell, the article's author, concludes, "As more consumers have fears about security on the Internet, viruses and malware, they may be happy to opt for Apple's gated community."

Jailbreaking

For more details on iPad Jailbreaking, see iOS jailbreaking.

Like other iOS Devices, the iPad can be "jailbroken", allowing applications and programs that are not authorized by Apple to run on the device. Once jailbroken, iPad users are able to download many applications previously unavailable through the App Store via unofficial installers such as Cydia, as well as illegally pirated applications      (SONY VAIO VGN-FZ38M Battery)        .

Apple claims jailbreaking voids their factory warranty on the device in the United States.

Books, news, and magazine content

Reading a book on the iPad

Further information: iBookstore

The iPad has an optional iBooks application that can be downloaded from the App Store, which displays books and other ePub-format content downloaded from the iBookstore.  For the iPad launch on April 3, 2010, the iBookstore is available only in the United States   (SONY VAIO VGN-FZ21m Battery)          .

Several major book publishers including Penguin Books, HarperCollins, Simon & Schuster and Macmillan have committed to publishing books for the iPad.

In February 2010, Condé Nast Publications said it would sell iPad subscriptions for its GQ, Vanity Fair and Wired magazines by June.  In April 2010, The New York Times announced it will begin publishing daily on the iPad         (SONY VAIO VGN-FZ18m Battery)  .

Major news organizations, such as The Wall Street Journal, BBC, and Reuters have released iPad applications, to varying degrees of success.

Censorship

Further information: Apple App Store censorship

Apple's App Store, which provides iPhone and iPad applications, imposes censorship of content, which has become an issue for book publishers and magazines seeking to use the platform. The Guardian described the role of Apple as analogous to that of the distributor WH Smith, a main distributor which for many years imposed content restrictions on British publishers      (SONY VAIO VGN-FZ11m Battery)         .

Pornography on the iPad

Due to the exclusion of porn from the App Store, YouPorn and others changed their video format from Flash to H.264 and HTML5 specifically for the iPad. In an e-mail exchange[78] with Ryan Tate from Valleywag, Steve Jobs claimed that the iPad offers "freedom from porn", leading to many upset replies including Adbustings in Berlin by artist Johannes P. Osterhoff  and in San Francisco during WWDC10        (SONY VAIO VGN-FZ11z Battery)           .

Release

Apple began taking pre-orders for the iPad from U.S. customers on March 12, 2010.  The only major change to the device between its announcement and being available to pre-order was the addition of a rotation lock in place of the mute button. The Wi-Fi version of the iPad went on sale in the United States on April 3, 2010. The Wi-Fi + 3G version was released on April 30       (SONY VAIO VGN-FZ11l Battery)       .

3G service in the United States is provided by AT&T and was initially sold with two prepaid contract-free data plan options: one for unlimited data and the other for 250 MB per month at half the price.  On June 2, 2010, AT&T announced that effective June 7 the unlimited plan would be replaced for new customers with a 2 GB plan at slightly lower cost; existing customers would have the option to keep the unlimited plan      (SONY VAIO VGN-FZ31z Battery)                     .

The plans are activated on the iPad itself and can be canceled at any time.

The iPad was launched in Australia, Canada, France, Germany, Italy, Japan, Spain, Switzerland and the United Kingdom on May 28.  Online pre-orders in those countries began on May 10. Apple released the iPad in Austria, Belgium, Hong Kong, Ireland, Luxembourg, Mexico, Netherlands, New Zealand and Singapore on 23 July 2010       (Dell Studio 1555 Battery)        .

Israel briefly prohibited importation of the iPad because of concerns that its Wi-Fi might interfere with other devices.  On September 17, 2010 the iPad officially launched in China.

The device was initially popular with 300,000 iPads being sold on their first day of availability.  By May 3, 2010 Apple had sold a million iPads,  this was in half the time it took Apple to sell the same number of original iPhones. By May 31, 2010 Apple had sold two million iPads and by June 22, 2010 they had sold 3 million     (Dell Vostro 1720 Battery)          .

The South Korean Minister of Ministry of Culture and Tourism, Yu In-chon was criticized for using an "unapproved" iPad on a public occasion; it is illegal to use an unapproved electronic device in South Korea.

Reception

Reaction to the announcement

Media reaction to the iPad announcement was mixed. Walt Mossberg wrote, "It's about the software, stupid", meaning hardware features and build are less important to the iPad's success than software and user interface, his first impressions of which were largely positive. Mossberg also called the price "modest" for a device of its capabilities, and praised the ten-hour battery life    (Dell Vostro 1500 Battery)          .

Others, including PC Advisor and The Sydney Morning Herald, wrote that the iPad would also compete with proliferating netbooks, most of which use Microsoft Windows. The base model's $499 price was lower than pre-release estimates by the tech press, Wall Street analysts, and Apple's competitors, all of whom were expecting a much higher entry price point     (Dell Latitude D830 Battery)   .

Yair Reiner said the iPad will compete against e-book devices such as the Barnes & Noble nook and the Amazon Kindle while offering 70 percent of revenue to publishers, the same arrangement afforded developers on the Apple App Store. Notably, a week before the iPad's expected release, the Amazon Kindle store increased publishers' revenue share to 70 percent as well       (Dell Latitude D620 Battery)             .

Several days after the unveiling, Stephen Fry said people must use the iPad to truly appreciate its purpose and quality and commented that common criticisms of the device fall away after use. Fry noted the iPad's speed and responsiveness, the intuitive interface and the richness and detail of the display. Along with Steve Jobs' statements in the announcement members of the media also said that it established a new class of devices between smartphones and laptops        (SONY VAIO VGN-FZ150E Battery)         .

Reviews

Reviews of the iPad have been generally favorable. Walt Mossberg of The Wall Street Journal called it a "pretty close" laptop killer.  David Pogue of The New York Times wrote a "dual" review, one part for technology-minded people, and the other part for non-technology-minded people. In the former section, he notes that a laptop offers more features for a cheaper price than the iPad       (Dell Studio 1735 Battery)          .

In his review for the latter audience, however, he claims that if his readers like the concept of the device and can understand what its intended uses are, then they will enjoy using the device. Ed Baig of USA Today bluntly states that the iPad "is a winner". Andy Ihnatko of the Chicago Sun-Times calls the iPad "one of the best computers ever"        Sony VGN-FZ31Z Battery)        .

PC Magazine's Tim Gideon wrote, "you have yourself a winner" that "will undoubtedly be a driving force in shaping the emerging tablet landscape."[112] Michael Arrington of TechCrunch said, "the iPad beats even my most optimistic expectations. This is a new category of device. But it also will replace laptops for many people     (Dell Inspiron 300M Battery)      ."

PC World criticized the iPad's slim file-sharing and printing abilities, and Ars Technica said sharing files with a computer is "without a doubt one of our least favorite parts of the iPad experience."

Reaction to the international launch

On May 28, 2010 the iPad was released in Australia, Canada, Japan as well as several larger European countries. Media reaction to the launch was mixed. The media noted the positive response from fans for the device with thousands of people queued on the first day of sale in a number of these countries       (Dell Studio 1737 battery)     .

The media also praised the quantity of applications, as well as the bookstore and other media applications.  In contrast they criticized the iPad for being a closed system and mentioned that the iPad faces competition from Android based tablets.  With regards to its books application The Independent criticized the iPad for not being as readable in bright light as paper. However they also praised the device for being able to store a large number of different books         (Dell XPS M1530 battery)      .

Omitted features

CNET and Gizmodo listed features that are missing from the iPad that they believe customers expect, including a camera for video chat, Adobe Flash support, a longer and narrower "widescreen" aspect ratio suitable for watching widescreen movies, and the ability to multitask (run more than one application at once), a USB port, HDMI output, and a more flexible wired-data port than the iPod dock connector          (Dell XPS M2010 battery)       .

According to Apple's iOS 4 unveiling and demonstration on April 8, 2010, as well as the Keynote presentation available on their website, multitasking will be available to all iPad users with a software update in the fall of 2010. The Seattle Post-Intelligencer and Gizmodo noted that the iPad will officially support installing software only from the App Store           (Dell Vostro 1000 battery)          .

CNET also criticised the iPad for its apparent lack of wireless sync which other portable devices such as Microsoft's Zune have had for a number of years. The built-in iTunes app is able to download from the Internet as well.

CNN and Wired News defended Apple's omission of a number of features, including support for Adobe Flash, noting that YouTube and Vimeo have switched to H.264 for video streaming         (HP Pavilion dv9000 battery)   .

They also said that " will not matter at all to the target user", as its absence is responsible for "a large part of [the iPad's] ten-hour battery life." Multitasking will be added in the next iPad software update. Of the aspect ratio: "16:9 ratio in [portrait mode] would look oddly tall and skinny ... [4:3 is] a compromise, and a good one." Of the lack of a USB port: "The iPad is meant to be an easy-to-use appliance, not an all-purpose computer. A USB port would mean installing drivers for printers, scanners and anything else you might hook up         (Hp 520 battery)     ."

People have been divided over whether to consider the iPad a personal computer. Forrester Research has argued that the iPad should be considered a form of personal computer in spite of Apple's restrictions on creating and editing files with the iPad.  In contrast PC World have argued that the iPad isn't a personal computer due to it omitting several key features including multitasking and support for Adobe Flash         (SONY VGP-BPS13 Battery)     .

Product name

Like the iPhone, the iPad shares its name with existing products. The most publicized is the Fujitsu iPAD, a mobile multi-functional device sold to retailers to help clerks verify prices, check inventory, and close sales. The Japanese company Fujitsu introduced the iPAD in 2002, and the following year applied for the trademark, but the firm found the mark was already owned by Mag-Tek. Fujitsu's trademark application was listed as "abandoned" in April 2009, and the ownership of the mark is unclear          (SONY VAIO VGN-FZ Battery)        .

Fujitsu consulted attorneys over what, if any, action it might take.  On March 17, 2010 the Fujitsu iPAD U.S. trademark was transferred to Apple.

In the first days after the iPad's announcement, some media and many online commenters criticized the name "iPad", noting its similarity to "pad", the common name for a sanitary napkin.  Shortly after the launch announcement, the hashtag "iTampon" became the number-two trending topic on the social networking site Twitter        (Dell RM791 battery)        .

Available Locations

The iPad was initially only available online at The Apple Store as well as the companys' retail locations. The iPad has become available in retail outlets such as Target and Best Buy.

Usage

Business

While the iPad is mostly used by consumers it also has been taken up by business users. Some companies are adopting iPads in their business offices by distributing or making available the iPads to employees. Examples of uses in the workplace include attorneys responding to clients, medical professionals accessing health records during patient exams, and managers approving employee requests            (Toshiba Portege R200 Battery)     .

Children

The iPad has several uses in the classroom , and has been praised as a valuable tool for homeschooling.  Several iPad apps have been developed just for children, like Cat in the Hat, Baby Flashcards, and the Miss Spider apps. Soon after the iPad was released, it was reported that 81% of the top book apps were for children. The iPad has also been called a revolutionary tool to help children with autism learn how to communicate and socialize more easily     (Toshiba Satellite M60 battery)             .

Operation

A mouse typically controls the motion of a cursor in two dimensions in a graphical user interface (GUI). Clicking or hovering (stopping movement while the cursor is within the bounds of an area) can select files, programs or actions from a list of names, or (in graphical interfaces) through small images called "icons" and other elements       (Dell XPS M1210 Battery)       .

For example, a text file might be represented by a picture of a paper notebook, and clicking while the cursor hovers this icon might cause a text editing program to open the file in a window      .

Users can also employ mice gesturally; meaning that a stylized motion of the mouse cursor itself, called a "gesture", can issue a command or map to a specific action. For example, in a drawing program, moving the mouse in a rapid "x" motion over a shape might delete the shape      (Dell Studio XPS 1340 Battery)         .

Gestural interfaces occur more rarely than plain pointing-and-clicking; and people often find them more difficult to use, because they require finer motor-control from the user. However, a few gestural conventions have become widespread, including the drag-and-drop gesture, in which     (Dell Studio XPS 1640 Battery)         :

The user presses the mouse button while the mouse cursor hovers over an interface object

The user moves the cursor to a different location while holding the button down

The user releases the mouse button

For example, a user might drag-and-drop a picture representing a file onto a picture of a trash can, thus instructing the system to delete the file        (Dell Vostro 1710 Battery)         .

Other uses of the mouse's input occur commonly in special application-domains. In interactive three-dimensional graphics, the mouse's motion often translates directly into changes in the virtual camera's orientation. For example, in the first-person shooter genre of games (see below), players usually employ the mouse to control the direction in which the virtual player's "head" faces    (ASUS EEE PC900 battery)           :

moving the mouse up will cause the player to look up, revealing the view above the player's head. A related function makes an image of an object rotate, so that all sides can be examined.

When mice have more than one button, software may assign different functions to each button       (Dell RM791 battery)     .

Often, the primary (leftmost in a right-handed configuration) button on the mouse will select items, and the secondary (rightmost in a right-handed) button will bring up a menu of alternative actions applicable to that item. For example, on platforms with more than one button, the Mozilla web browser will follow a link in response to a primary button click, will bring up a contextual menu of alternative actions for that link in response to a secondary-button click, and will often open the link in a new tab or window in response to a click with the tertiary (middle) mouse button    (Sony VGP-BPS13 battery)        .

Different ways of operating the mouse cause specific things to happen in the GUI:

Click: pressing and releasing a button.

(left) Single-click: clicking the main button.

(left) Double-click: clicking the button two times in quick succession counts as a different gesture than two separate single clicks.

(left) Triple-click: clicking the button three times in quick succession    (sony vgp-bpl9 battery)         .

Right-click: clicking the secondary button.

Middle-click: clicking the ternary button.

Drag: pressing and holding a button, then moving the mouse without releasing. (Use the command "drag with the right mouse button" instead of just "drag" when you instruct a user to drag an object while holding the right mouse button down instead of the more commonly used left mouse button       (Sony VGP-BPL11 battery)        .

Button chording (a.k.a. Rocker navigation).

Combination of right-click then left-click.

Combination of left-click then right-click or keyboard letter.

Combination of left or right-click and the mouse wheel         (Sony VGP-BPL15 battery)      .

Clicking while holding down a modifier key.

Standard semantic gestures include :

Rollover

Selection

Menu traversal      (Dell Inspiron E1505 battery )

Drag and drop

Pointing

Goal crossing

Multiple-mouse systems

Some systems allow two or more mice to be used at once as input devices. 16-bit era home computers such as the Amiga used this to allow computer games with two players interacting on the same computer. The same idea is sometimes used in collaborative software, e.g. to simulate a whiteboard that multiple users can draw on without passing a single mouse around        (Dell Latitude E6400 battery)           .

Microsoft Windows, since Windows 98, has supported multiple simultaneous pointing devices. Because Windows only provides a single screen cursor, using more than one device at the same time generally results in seemingly random movements of the cursor. However, the advantage of this support lies not in simultaneous use, but in simultaneous availability for alternate use   (HP Pavilion dv6000 Battery)         :

for example, a laptop user editing a complex document might use a handheld mouse for drawing andmanipulation of graphics, but when editing a section of text, use a built-in trackpad to allow movement of the cursor while keeping his hands on the keyboard. Windows' multiple-device support means that the second device is available for use without having to disconnect or disable the first   (Hp Pavilion dv3-1000 battery)           .

As of 2009, Linux distributions and other operating systems that use X.Org, such as OpenSolaris and FreeBSD, support unlimited numbers of cursors and keyboards through Multi-Pointer X.

There have also been propositions of having a single operator use two mice simultaneously as a more sophisticated means of controlling various graphics and multimedia applications       (Dell Precision M70 Battery)         .

Buttons

Main article: mouse button

Mouse buttons are microswitches which can be pressed ("clicked") in order to select or interact with an element of a graphical user interface.

The three-button scrollmouse has become the most commonly available design         (Acer Aspire One battery)       .

As of 2007 (and roughly since the late 1990s), users most commonly employ the second button to invoke a contextual menu in the computer's software user interface, which contains options specifically tailored to the interface element over which the mouse cursor currently sits  . By default, the primary mouse button sits located on the left-hand side of the mouse, for the benefit of right-handed users; left-handed users can usually reverse this configuration via software      (Hp 520 battery)         .

Mouse speed

The computer industry often measures mouse sensitivity in terms of counts per inch (CPI), commonly expressed less correctly as dots per inch (DPI) – the number of steps the mouse will report when it moves one inch. In early mice, this specification was called pulses per inch (ppi)        (Toshiba Satellite L305 Battery)         .

If the default mouse-tracking condition involves moving the cursor by one screen-pixel or dot on-screen per reported step, then the CPI does equate to DPI: dots of cursor motion per inch of mouse motion. The CPI or DPI as reported by manufacturers depends on how they make the mouse; the higher the CPI, the faster the cursor moves with mouse movement           (Toshiba Satellite Pro M15 Battery)         .

However, software can adjust the mouse sensitivity, making the cursor move faster or slower than its CPI. Current software can change the speed of the cursor dynamically, taking into account the mouse's absolute speed and the movement from the last stop-point. In most software[specify] this setting is named "speed", referring to "cursor precision"         (Toshiba Satellite M65 battery)        .

However, some software[specify] names this setting "acceleration", but this term is in fact incorrect. The mouse acceleration, in the majority of mouse software, refers to the setting allowing the user to modify the cursor acceleration: the change in speed of the cursor over time while the mouse movement is constant       (Toshiba Satellite T4900 Battery)       .

For simple software, when the mouse starts to move, the software will count the number of "counts" received from the mouse and will move the cursor across the screen by that number of pixels (or multiplied by a rate factor, typically less than 1). The cursor will move slowly on the screen, having a good precision        (Toshiba PA3399U-2BRS battery)        .

When the movement of the mouse passes the value set for "threshold", the software will start to move the cursor more quickly, with a greater rate factor. Usually, the user can set the value of the second rate factor by changing the "acceleration" setting.

Operating systems sometimes apply acceleration, referred to as "ballistics", to the motion reported by the mouse     (Toshiba Satellite A200 Battery)         .

For example, versions of Windows prior to Windows XP doubled reported values above a configurable threshold, and then optionally doubled them again above a second configurable threshold . These doublings applied separately in the X and Y directions, resulting in very nonlinear response      (Toshiba Satellite 1200 Battery)     .

Starting with Windows XP and for many OS versions for Apple Macintosh, computers use a ballistics calculation that compensates for screen-resolution in a slightly different way, which affects the way the mouse feels.[citation needed] Ballistics are further affected by the choice of driver software       (Toshiba NB100 Battery)         .

Mousepads

Main article: Mousepad

Engelbart's original mouse did not require a mousepad; the mouse had two large wheels which could roll on virtually any surface. However, most subsequent mechanical mice starting with the steel roller ball mouse have required a mousepad for optimal performance       (Toshiba Satellite M300 Battery)         .

The mousepad, the most common mouse accessory, appears most commonly in conjunction with mechanical mice, because in order to roll smoothly, the ball requires more friction than common desk surfaces usually provide. So-called "hard mousepads" for gamers or optical/laser mice also exist       (Dell INSPIRON 1525 battery)          .

Although most optical and laser mice do not require a pad, some users find that using a mousepad provides more comfort and less jitter of the cursor on the display. Whether to use a hard or soft mousepad with an optical mouse is largely a matter of personal preference. One exception occurs when the desk surface creates problems for the optical or laser tracking, for example, a transparent or reflective surface         (SONY VAIO VGN-FZ280E Battery)     .

Other cases may involve keeping desk or table surfaces free of scratches and deterioration; when the grain pattern on the surface causes inaccurate tracking of the cursor, or when the mouse-user desires a more comfortable mousing surface to work on and reduced collection of debris under the mouse         (SONY VAIO VGN-FZ410 Battery)       .

In the marketplace

Around 1981 Xerox included mice with its Xerox Star, based on the mouse used in the 1970s on the Alto computer at Xerox PARC. Sun Microsystems, Symbolics, Lisp Machines Inc., and Tektronix also shipped workstations with mice, starting in about 1981. Later, inspired by the Star, Apple Computer released the Apple Lisa, which also used a mouse       (SONY VAIO VGN-FZ160 Battery)      .

However, none of these products achieved large-scale success. Only with the release of the Apple Macintosh in 1984 did the mouse see widespread use.

The Macintosh design, commercially successful and technically influential, led many other vendors to begin producing mice or including them with their other computer products (in 1985, Atari ST, Commodore Amiga, Windows 1.0, and GEOS for the Commodore 64). The widespread adoption of graphical user interfaces in the software of the 1980s and 1990s made mice all but indispensable for controlling computers      (SONY VAIO VGN-FZ38M Battery)       .

In November 2008, Logitech built their billionth mouse .

Englebart's mouse did use a mouse pad. In 1968, Jack Kelley, from the Herman Miller Research Division located in Ann Arbor, MI, designed a portable console for computer input, that could be used in a variety locations. The console also attached to an office chair which Englebart used in his presentation to the 1968 Fall Computer Conference in San Francisco. The console consisted of a keyboard and two platforms for the usage of the "mouse". These platforms, surfaces with naugahide (vinyl) were the first pads designed specifically for mouse operation         (SONY VAIO VGN-FZ21m Battery)         .

Use in gaming

Mice often function as an interface for PC-based computer games and sometimes for video game consoles.

First-person shooters

Due to the cursor-like nature of the crosshairs in first-person shooters (FPS), a combination of mouse and keyboard provides a popular way to play FPS games. Players use the X-axis of the mouse for looking (or turning) left and right, leaving the Y-axis for looking up and down          (SONY VAIO VGN-FZ18m Battery)         .

The left button usually controls primary fire. Many gamers prefer this primarily in FPS games over a gamepad or joypad because it allows them to look around easily, quickly and accurately. If the game supports multiple fire-modes, the right button often provides secondary fire from the selected weapon. The right button may also provide bonus options for a particular weapon, such as allowing access to the scope of a sniper rifle or allowing the mounting of a bayonet or silencer      (SONY VAIO VGN-FZ11m Battery)      .

Gamers can use a scroll wheel for changing weapons, or for controlling scope-zoom magnification. On most FPS games, programming may also assign more functions to additional buttons on mice with more than three controls. A keyboard usually controls movement (for example, WASD, for moving forward, left, backward and right, respectively) and other functions such as changing posture     (SONY VAIO VGN-FZ11z Battery)        .

Since the mouse serves for aiming, a mouse that tracks movement accurately and with less lag (latency) will give a player an advantage over players with less accurate or slower mice.

An early technique of players, circle strafing, saw a player continuously strafing while aiming and shooting at an opponent by walking in circle around the opponent with the opponent at the center of the circle      (SONY VAIO VGN-FZ11l Battery)         .

Players could achieve this by holding down a key for strafing while continuously aiming the mouse towards the opponent.

Games using mice for input have such a degree of popularity that many manufacturers, such as Logitech, Cyber Snipa, Razer USA Ltd and SteelSeries, make peripherals such as mice and keyboards specifically for gaming. Such mice may feature adjustable weights, high-resolution optical or laser components, additional buttons, ergonomic shape, and other features such as adjustable DPI          (SONY VAIO VGN-FZ31z Battery)            .

Many games, such as first- or third-person shooters, have a setting named "invert mouse" or similar (not to be confused with "button inversion", sometimes performed by left-handed users) which allows the user to look downward by moving the mouse forward and upward by moving the mouse backward (the opposite of non-inverted movement)      (Dell Studio 1555 Battery)        .

This control system resembles that of aircraft control sticks, where pulling back causes pitch up and pushing forward causes pitch down; computer joysticks also typically emulate this control-configuration.

After id Software's Doom, the game that popularized FPS games but which did not support vertical aiming with a mouse (the y-axis served for forward/backward movement), competitor 3D Realms' Duke Nukem 3D became one of the first games that supported using the mouse to aim up and down     (Dell Vostro 1720 Battery)           .

This and other games using the Build engine had an option to invert the Y-axis. The "invert" feature actually made the mouse behave in a manner that users now regard as non-inverted (by default, moving mouse forward resulted in looking down). Soon after, id Software released Quake, which introduced the invert feature as users now know it. Other games using the Quake engine have come on the market following this standard, likely due to the overall popularity of Quake       (Dell Vostro 1500 Battery)    .

Home consoles

In 1988 the educational video game system, the VTech Socrates, featured a wireless mouse with an attached mouse pad as an optional controller used for some games. In the early 1990s the Super Nintendo Entertainment System video game system featured a mouse in addition to its controllers. The Mario Paint game in particular used the mouse's capabilities, as did its successor on the Nintendo 64. Sega released official mice for their Genesis/Mega Drive, Saturn and Dreamcast consoles      (Dell Latitude D830 Battery)        .

NEC sold official mice for its PC Engine and PC-FX consoles. Sony Computer Entertainment released an official mouse product for the PlayStation console, and included one along with the Linux for PlayStation 2 kit. However, users can attach virtually any USB mouse to the PlayStation 2 console. In addition the PlayStation 3 also fully supports USB mice. Recently the Wii also has this latest development added on in a recent software update      (Dell Latitude D620 Battery)          .