Pawns move forward, but capture diagonally. They can
only capture one square diagonally in front of them.
If there is another piece directly in front of a pawn, he can't
capture that piece.
Pawns can only move forward one square at a time, except for their very first move where they can move forward two squares. If there is another piece directly in front of a pawn, he cannot move past.
En Passant - In Passing
This rule about Pawns is called "en passant"
(French), which basically means "in passing":
if a Pawn moves out two squares on its first
move, and by doing so lands to the side of an
opponent's Pawn (effectively jumping past the
other Pawn's ability to capture it), that other
pawn has the option of capturing the first Pawn
as it passes by.
This special move must be done immediately after
the first Pawn has moved past, otherwise the
option to capture it is no longer available.
Only Pawns may be promoted. If a Pawn reaches the other side of the board, it can become any other chess piece (called promotion). A Pawn may be promoted to any piece (Queen, Rook, Bishop or Knight).
Movements of the King
Ajedrez - Chess