What Does Function Key (F Key) Mean?
A function key refers to one of the twelve keys present on the top row of a common PC keyboard. Labeled from F1–F12, these function keys are responsible for performing shortcut tasks like printing or saving files. Different operating systems, for example Windows and Mac OS, have separate uses for function keys.
A function key is also known as a soft key.
Techopedia Explains Function Key (F Key)
Function keys are present on all modern Mac and Windows keyboards. On some laptop keyboards, however, they are not separate keys but are sub-functions of other keys and can be activated with the help of a separate key, usually the Fn key. In the top row of a regular keyboard, function keys help with the performance of various functions; for example, Microsoft Windows users can press ALT + F4 to close the program currently active. Apple computers did not have function keys in earlier models, but current keyboards feature the function keys on the top row similar to the standard PC keyboard.