— the presence on the keyboard of the Fn key (short for function). It belongs to modifiers, similar to Shift or Ctrl: by itself it does not perform any action, but when pressed simultaneously with another key, it changes its original purpose. Fn is often found in compact keyboards (see "Format"), but can also be set in full-sized ones. The features it provides include quickly changing the screen brightness or sound volume directly from the keyboard, using the centre keys as a Numpad, launching individual applications, and so on. Specific features of using the Fn key depend on the keyboard model.
