The pawn is the most numerous piece in chess: each player starts with eight, placed on the second rank (White) or the seventh rank (Black). It is also the least valuable piece, worth approximately 1 point on the standard material scale.
A pawn moves straight forward, one square at a time — or two squares from its starting position — but captures diagonally, one square forward. It cannot move backward. Two special rules apply: en passant allows a pawn to capture an adjacent enemy pawn that has just advanced two squares, and promotion turns any pawn that reaches the last rank into any other piece, almost always a queen.
In practice, pawns define the shape of the game. How they are arranged — in chains, isolated, doubled, or passed — determines the plans available to both sides. Players in the 800–1400 ELO range gain a great deal by paying attention to their pawn structure from the very first moves: avoid unnecessary doubled pawns, watch out for isolated pawns, and recognize passed pawns as a potential endgame asset.