Check, mate and stalemate
The goal of chess isn't to eat pieces: it's to checkmate the enemy king. Here we tell apart the three situations every beginner confuses.
Check: the king is attacked and must be saved, no matter what. Checkmate: it's attacked and there's no way to save it — end of game. Stalemate: the king is NOT attacked but has no legal move left — and that's a draw, an outcome that often gives away half a point.