Alpha-Beta pruning is an optimization technique used in the minimax algorithm for decision-making, primarily in two-player games like chess. It reduces the number of nodes evaluated in the search tree by "pruning" branches that won’t affect the final decision.

Alpha represents the best value a maximizing player can guarantee, while Beta represents the best value a minimizing player can guarantee. When the current branch’s value is worse than the previously examined options (for either player), that branch is cut off, saving computational resources without compromising accuracy. This makes the algorithm faster and more efficient in complex scenarios.