TicTacToe is a two-player game where players take turns placing their markers, usually an "X" and an "O", on a 3x3 grid. Each player aims to get three of their markers in a row, column, or diagonal line before the other player does.

The game starts with one player placing their marker on the grid, followed by the other player placing their marker. The game continues in this way until one player successfully gets three of their markers in a row, column, or diagonal line, resulting in that player winning the game.

If all of the cells on the grid are filled with markers and no player has been able to get three markers in a row, column, or diagonal line, then the game ends in a draw.

In summary, TicTacToe is a simple yet exciting game that requires strategy and careful planning to win.