... a double attack
A double attack poses two threats at once. The defending side is not able to respond to both threats simultaneously. The knight fork is perhaps the most common type of double attack.
The queen's mobility makes it a powerful weapon for creating double attacks.
In this position White sets up a double attack which prompted Black to resign. How ?
When there is a double check the opponent's king must move.
White uses a double check to force checkmate in this entertaining game