When a pawn reaches the 8th rank (for White) or 1st rank (for Black), it promotes and can be exchanged for any piece except a King. A pawn moving from D2 to D8 describes a White pawn reaching the promotion square on the 8th rank. According to chess rules, the player can choose to promote this pawn to a Queen, Rook, Bishop, or Knight - any White piece except the King. This is called pawn promotion.