Exchanging pieces when material behind
When you are ahead, trade pieces if you want to get to an endgame with more pawns.
If you are behind, trade pawns to reduce the risk of them promoting. It is a draw if they are ahead +3 but they are left with a king and knight (or bishop) and you just have a king.
(at least that is why the guy "Chess Vibes" says on youTube).