Black to move
Black must play 1...Ke6, and then after 2.Kxf4, Black moves in front of the enemy king, 2...Kf6.
White to move
This position is a draw if White is the player to move. If it is Black's turn, White wins. Move the pieces one square further up, and the same is true. Move the pieces to another file, and it is still true for every file except the a-file and the h-file.
Memorize this position. You will see it in your games.