What means Check?

When a king is attacked, it is called check. Check can be viewed as saying "Watch out! The king is attacked!" Since a king can never be captured, the term "check" is used when a king is threatened. In this tournament you have to check the king with your queen or you will lose your games. Link for to enter the tournament: https://www.chess.com/tournament/give-check-with-your-queen-and-you-will-win