Swordfish

expert tier

Look at the pencil marks in the six highlighted cells. Across these three rows, digit 5 only appears as a candidate in the very same three columns.

That locks 5 into one cell per row among just those three columns — like a bigger version of an X-Wing. Either way it works out, 5 can be crossed off the rest of those columns, including the marked cell (which still has other candidates left).

Next: XY-Wing

Practice with a puzzle