A pawn fork is a double attack by a pawn. A pawn captures diagonally, to the left or to the right. When two enemy pieces are on the same rank, separated by one square, a pawn can fork them. The pawn is like a fork with two teeth, pricking into the pieces.
Since pawns are worth so little, pawn forks nearly always win you material. Even when you lose your pawn. So always be on the lookout for pawn fork opportunities. And don’t forget: pawns may move two squares ahead from their starting position.
What do you have to do?
Attack two pieces with a pawn fork and win material.