Function Lock, often abbreviated as Fn Lock or F Lock, is a feature that allows users to lock the Function key in a pressed or unpressed state. When the Function Lock is enabled, users can access the function keys' secondary functions (usually indicated by icons or symbols on the keys) without needing to press the Fn key simultaneously. Conversely, when it's disabled, the function keys default to their primary functions, often requiring the Fn key to be pressed in combination with the function key to access the secondary functions.