The Shapley value is a concept from cooperative game theory that helps determine how to fairly distribute a total payoff among players who contribute to a joint effort. It calculates each player's contribution by considering all possible combinations of players and their contributions to the overall success. This ensures that each player receives a share that reflects their individual impact on the group's outcome. Developed by mathematician Lloyd Shapley in 1953, the Shapley value is widely used in various fields, including economics, political science, and machine learning. It provides a systematic way to allocate resources or rewards, promoting fairness and cooperation among participants in collaborative scenarios.