Skewer
A skewer is like a pin in reverse: you attack a valuable piece, and when it steps aside, you grab the less valuable piece that was hiding behind it. It works in a straight line, so bishops, rooks, and queens do the skewering.
The rook checks the king along the a-file. When the king steps aside, the rook captures the queen that was hiding behind it — a skewer, a pin in reverse.
Source for further study: Bain, Chess Tactics for Students, ch. 3.