What Is a Computer Keyboard?

A computer keyboard is a device originally used for inputting text into a computer. While its primary function remains the same today, keyboards are also used for other tasks, such as navigating documents and switching between programs. Although all keyboards have their origin in the typewriter, today many varieties of keyboards are available.

History

The keyboards used with computers evolved from the typewriter. The first keyboards were designed to be used with simple terminals: text-driven computers that had little or no support for graphics beyond the 26 letters of the English alphabet in upper and lowercase, numbers, and punctuation. The user typed a command and hit Return to execute it.

Evolution

As computers evolved beyond simple text-based commands, the input device had to evolve, too. Keyboards gained modifier keys like Alt (short for "alternate") and Control (usually abbreviated "Ctrl"), which made it possible to access special functions in programs. As word-processing programs were made available, arrow keys were added to make navigating documents easier.

Localization

The keyboard most common in the U.S. today is the QWERTY keyboard, specifically the American version. This version of the keyboard is sometimes referred to as an ANSI QWERTY keyboard, referring to the American National Standards Institute, the organization that standardized the keyboard. In Europe, ISO QWERTY keyboards are more common, which usually have a Return key shaped like a backwards L and a key between Z and the left Shift. Some countries, such as France (which uses ISO AZERTY) and Germany (which uses ISO QWERTZ), have rearranged keys on the keyboard to accommodate the national languages.

Mechanics

Mechanically speaking, computer keyboards are fairly simple. The top of the key, usually referred to as a keycap, is depressed to make contact with a small 'switch' beneath it. The computer's circuitry, connected to the keyboard, detects this press and processes it accordingly.

Appearance

Regionality aside, keyboards come in a variety of styles. The keycaps may be fairly flat, as is the case with most laptops like Apple's MacBook Pro line and the iBooks before that. Some laptops, such as Apple's regular MacBook line, have keyboards with separated keys that extend down on the sides a bit, called "chiclet keyboards." Most desktop computers have keyboards with slight indents on the tops of the keys, which extend down on the sides instead.