Chinups & Lat pulldowns will make your lats wider, but if you want a thick, densely muscled back, you need to do rows. The T-bar row allows you to use a neutral grip—palms facing each other—which is the biomechanically strongest position to pull from.
The different grips will help target different areas on the Back. Close Grip will hit more Lat. Wider Overhand Grip will hit more Back. Now, you will still hit the Lats and back with both grips, however, that is the basic concept to start from. This is an exercise done to build! To help widen the Wing Span and Create the Turtle Shell! But always remember to make the mind to muscle connection during each rep and not just move the weight to move it.
Make the Connection! Feel the Movement and then Start moving some Weight!!