Function key

Function keys are a set of special keys on a computer keyboard which can be programmed so as to cause an application program to perform certain pre-defined actions.

Description
Function keys on the keyboard of a may be preset to generate short fixed sequences of characters, often beginning with the escape character (ASCII 27), or the characters they generate may be configured by sending special character sequences to the terminal.

On a microcomputer keyboard, the function keys may generate a fixed, single byte code, outside the normal ASCII range, which is translated into some other configurable sequence by the keyboard device driver or interpreted directly by the application program.

History
Early function keys were popularized by IBM in 1971 with the Programmed Function Keys (PF keys) of its terminal.