final is an adjective, "Mother will make the final decision."
Finish can be used as a verb, to finish, or an adjective, "the finish line"and a noun, " close finish in the speed skating at the Olympic games.
End is also a verb, "to end the game", an adjective, "end product" and a noun, "the end of the concert". They all mean the same yet we do not use them interchangeably.