Tic-Tac-Toe is a classic two-player strategy game played on a 3x3 grid. Players take turns marking the grid with their symbol, either "X" or "O," aiming to be the first to form a row, column, or diagonal of three of their symbols. The game ends when one player achieves this or when the grid is fully occupied, resulting in a draw. It's a simple yet engaging game that requires critical thinking and anticipation of your opponent's moves.