On a computer keyboard , a function key is one of a sequence of special keys labeled "F1" or higher (usually up to "F12" on most keyboards) that can be assigned a specific use in order to save a user time. Some function keys have uses assigned by an operating system such as Windows and somewhat different uses when interacting with an application program. In some cases, the meaning of a function key can be described by the user to an application program.
A function key may be assigned a second use when it is pressed in combination with the shift key, ALT key, or Control key. A function key is sometimes considered to be a form of hot key .