A chess engine is a computer program designed to analyze and play the game of chess. These engines use complex algorithms and vast databases of chess positions to evaluate potential moves and predict outcomes. They can play at a very high level, often surpassing even the best human players. Chess engines are commonly used for training, analysis, and game preparation. Players can input their games to receive feedback on their moves, while enthusiasts can challenge the engine to improve their skills. Popular chess engines include Stockfish and AlphaZero, which have significantly advanced the understanding of chess strategy.