Lock keys

computer key

computer key on IBM-compatible computer keyboards, originally used to make the arrow keys scroll the contents of a text window instead of moving the cursor

key on computer keyboards which enables or disables a numerical pad on the keyboard

computer key that toggles application state

thumb|256px|The F-Lock key on a Microsoft keyboard The F-Lock key, introduced by Microsoft in 2001, toggles the state of the function keys. When on, keys F1 to F12 behave as applicable, with meanings defined by the application being used at the time. When off, new behaviour is used: F5 means "open", F10 means "spell" etc. In early models, the state reverted to off at each reboot or keyboard reset, but later models retained F-Lock state across reboots.