What is a pawn in chess?

The pawns are the eight small pieces which form a row in front of the major pieces. In the battle analogy (and Chess is a battle) they are the poor bloody infantry who are sent into battle first. A pawn can move only one square forward , or diagonally forward to take another piece. On the first move theyare allowed to move two places forward if desired. This is to speed the game up.
A pawn is a piece on a chess board worth one point. Each side gets 8 pawns. A pawn can only move one square forward at a time, with the exception of it's first move, where it can move up to two squares forward.

A pawn can only capture one square diagonally in front of it. But in the case of 'en passant' where if the pawn is on the fifth rank and an opposing pawn moves two squares forward and ends up on either side of it, then it can capture that pawn as if it only moved one square.

Once a pawn reaches the other side of the board, it may be promoted to any piece of your choosing other than a king or pawn.

Pawns are the fundamental structure of a good chess game and should not be underestimated due to their low value.