Phase 8: Manipulators; Chapter 1: Pawns and Knights

No, you call check is whenever a piece of yours is threatening the opponent's king. As in, if they do nothing, the piece can capture it next turn. The opponent must move so that none of the opponent's pieces threaten the king.

Checkmate is when the king is in check and there is no legal move that will place the king out of check. The game then ends with the checkmated person losing. Stalemate on the other hand is when there is no legal move that will place the king out of check but the king is not currently in check. The game is then a draw.

To keep this post on topic: Thus metaphorically you can say that wizard is making a move that is threatening to "win" the game. One that his opponent did not even see.