In chess, "checkmate" occurs when a player's king is in a position to be captured and cannot escape. This means the king is under attack, or "in check," and there are no legal moves available to remove the threat. The game ends immediately when checkmate is declared. Achieving checkmate requires strategic planning and skillful maneuvering of pieces like the queen, rook, and bishop. Players aim to control the board and limit their opponent's options, ultimately trapping the king. Understanding checkmate patterns is essential for improving in chess and winning games.