How can a king capture another piece in chess?

A pawn captures another piece by moving diagonally one square forward to the square where the enemy piece is located. The pawn cannot capture a piece that is directly in front of it. Another way a pawn captures is under a special rule which applies only to another pawn. If White has a pawn on the 5th rank and Black moves a pawn one file over two spaces from the 7th rank to the 5th rank, the White pawn may capture the Black pawn even though the black pawn is now right beside it by moving one square diagonally forward right behind the Black pawn. This is called capturing "en passant"