What are the extreme tic-tac-toe rules and how do they differ from traditional tic-tac-toe rules?

Extreme tic-tac-toe is a variation of the classic game where each square of the board is its own smaller game of tic-tac-toe. Players must win three smaller games in a row to win the overall game. The main difference from traditional tic-tac-toe is the complexity and strategy involved, as players must think ahead and plan their moves carefully to win multiple games at once.