Answer:
On the top of every keyboard made in the last twenty years has been a row of Function or Fn keys. The came from the days when the only help you could get from a computer program came from pressing the Fn1 key if your were in WordPerfect, Fn3 if you were using Word. These days the Fn keys have been turned into Screen Brightness Up or Down, Video Start/ Stop/ Rewind, Volume Up / Down keys