How Computer Keyboards Work

A keyboard's primary function is to act as aninput device.Using a keyboard, a person can type a document, use keystroke shortcuts, access menus, play games and perform a variety of other tasks. Keyboards can have different keys depending on the manufacturer, theoperating systemthey're designed for, and whether they are attached to a desktop computer or part of a移动PC. But for the most part, these keys, also calledkeycaps, are the same size and shape from keyboard to keyboard. They're also placed at a similar distance from one another in a similar pattern, no matter what language or alphabet the keys represent.

Most keyboards have between 80 and 110 keys, including:

Thetyping keysinclude the letters of the alphabet, generally laid out in the same pattern used fortypewriters. According to legend, this layout, known asQWERTYfor its first six letters, helped keep mechanical typewriters' metal arms from colliding and jamming as people typed. Some people question this story -- whether it's true or not, the QWERTY pattern had long been a standard by the time computer keyboards came around.

Keyboards can also use a variety of other typing key arrangements. The most widely known isDvorak, named for its creator, August Dvorak. The Dvorak layout places all of the vowels on the left side of the keyboard and the most common consonants on the right. The most commonly used letters are all found along thehome row. The home row is the main row where you place your fingers when you begin typing. People who prefer the Dvorak layout say it increases their typing speed and reduces fatigue. Other layouts includeABCDE,XPeRT,QWERTZandAZERTY. Each is named for the first keys in the pattern. The QWERTZ and AZERTY arrangements are commonly used in Europe.

Thenumeric keypadis a more recent addition to the computer keyboard. As the use of computers in business environments increased, so did the need for speedy data entry. Since a large part of the data was numbers, a set of 17 keys, arranged in the same configuration found on adding machines and calculators, was added to the keyboard.

In 1986, IBM further extended the basic keyboard with the addition offunctionandcontrolkeys. Applications andoperating systemscan assign specific commands to the function keys. Control keys provide cursor and screen control. Fourarrowkeys arranged in an invertedTformation between the typing keys and numeric keypad move the cursor on thescreenin small increments.

Other common control keys include:

The Windows keyboard adds some extra control keys: twoWindowsorStartkeys, and anApplicationkey. Apple keyboards, on the other hand, haveCommand(also known as "Apple") keys. A keyboard developed for Linux users featuresLinux-specific hot keys, including one marked with "Tux" the penguin -- the Linux logo/mascot.