There's three major types of barbell rows:
-Yates row
-Coleman row
-Old School barbell row
I would rate the old school barbell row as the least effective of the three. This is where you bend over to a true 90 degrees and row the bar up, often standing on a bench. The Coleman row is medium grip overhand row at about 70 degrees to perpendicular, often using a swift movement generating a lot of momentum. The Yates row is a closer grip, underhand row at 70 degrees where the pull is much more isolated, with no body movement.
Overall, I'd rate the Coleman and Yates row equally effective. Coleman's style allows for more weight, but Yates' style is more strict. That being said, Yates style is more conducive to a bicep tear, so be careful with that.
Overall, the most important thing to remember when doing a barbell row, or any row for that matter, is that the spine must be arched back in order for the lats to fully contract.