A Minimax game is any turn-based two player game where the objective of one player is to maximize the evaluation score while the opponent tries to minimize it. Examples of such games include Chess, Go, TicTacToe, Connect Four, etc.
In this crate, there is a generic implementation of the minimax game-playing engine that can be used for any such games. The minimax algorithm is notorious for being slow so we speed it up using a pruning method called Alpha-Beta pruning.
The minimax algorithm under-the-hood tries to simulate every possible "best" gameplays from either sides and based on the results, recommends a move that should be played to best improve the winning chances of the player to move.
There is a caveat, in that, the minimax algorithm is too slow (since it explores the search space almost uncleverly). One optimization is that of pruning the search space by the means of a clever approach in which we "rule out gameplay sequences which the opponent won't definitely let us improve in." This is achieved by a technique called Alpha-Beta pruning.