When a humble pawn marches all the way to the opposite end of the board, it earns a massive reward — it gets promoted. As soon as the pawn touches the final row, it instantly evolves into another piece. You can choose to promote it into a queen, rook, bishop, or knight, and the new piece replaces the pawn on that final square. Because the queen is the strongest piece on the board, players almost always choose to promote to a queen.
For experienced players
“Under-promotion” (choosing a knight, rook, or bishop instead of a queen) is very rare, but choosing a knight is sometimes the winning move if it delivers an immediate check or a devastating fork.
See also:How the Pawn Moves·How the Queen Moves