Studying Rook Endings

Rook endings are vital to players seeking to improve.

How can Black draw this position? Black to move.

Just control the e-file: Re4 and make sure you do not get mated after Ke6

White can do no progress...

If needed black have to check the king from "behind" and in case the rooks are exchanged black have to know how to take the opposition and draw the game against king and pawn.

Re4. Black's Rook must stay in the contact with the White's pawn.

One of the most importamt endgames there are!

Indeed. The position is derived from Ending 56 in Jesus de la Villa, 100 Endgames You Must Know: Vital Lessons for Every Chess Player, 4th ed. (2015).

Here's an important position. White to move wins; Black to move draws.