Computer keyboard

Posted on at


In computing, a keyboard is a typewriter-style device, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the main input device for computers.

A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce lettersnumbers or signs (characters), other keys or simultaneous key presses can produce actions or execute computer commands.

Despite the development of alternative input devices, such as the mousetouchscreenpen devicescharacter recognition andvoice recognition, the keyboard remains the most commonly used device for direct (human) input of alphanumeric data into computers.

In normal usage, the keyboard is used as a text entry interface to type text and numbers into a word processortext editor or other programs. In a modern computer, the interpretation of key presses is generally left to the software. A computer keyboard distinguishes each physical key from every other and reports all key presses to the controlling software. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as WindowsControl-Alt-Deletecombination, which brings up a task window or shuts down the machine. A command-line interface is a type of user interface operated entirely through a keyboard, or another device doing the job of one.


TAGS:


About the author

160