Smart simplification
Having knowledge about pawn endgames is also useful when there are more pieces on the board. If you know that you can achieve a winning pawn endgame by exchanging pieces, you can steer towards that. The same applies the other way around. If you are not in a good position, but you see that you can reach a drawn pawn endgame, then it is beneficial to exchange pieces.
Exchanging pieces to move to a favorable endgame is called simplification.
In the first example we see that white simplifies into a winning pawn endgame by exchanging rooks.
In example 2, black saves half a point by fleeing into a king and pawn versus king endgame that is a draw.
What do you have to do?
Simplify into a winning pawn endgame.
Are you defending? Then simplify into a pawn endgame that you can draw.
The position looks equal at first glance, but exchanging rooks changes the situation completely. 1.Rd7+ Rxd7+ 2.Kxd7. This is example 1 from the 'conquer the pawn' lesson. Black is in zugzwang and has to release the pawn. White achieves the standard winning position: 2...Kf8 3.Kxe6 Ke8 4.Kd6 Kd8 5.e6 Ke8 6.e7 Kf7 7.Kd7 Kf6 8.e8Q.