Lets use anatomy to get this cleared up once and for all. There are three primary muscle groups of the back....1)
latissimus dorsi. The muscles of the outer back, attach near the armpit and look like wide 'wings' when fully developed. 2)
trapezius. The muscles of the upper back look like an irregular diamond-shape and when fully developed look like thick pythons forming on the upper back and wrapping around the neck. The rhomboids are underneath the trapezius and assist in scapular retraction 3)
erector spinae. Commonly reffered to as the 'lower back' these muscls actually run the entire lenght of the spine but are largest and most visible at the lower back area. The other muscle on the back are near the shoulders and are fairly small. (teres, infraspinitus, etc.)
To fully develop the back we need only a few exercises. Barbell rows work all the muscles in the back to some extent. As do deadlifts although since the upper arm moves very little, the lats will need additional work.
I work all the muscles of my back with only a few exercises.
Deadlifts hit the erector spinae and upper trapezius.
Chin-ups hit the lats, teres and lower trapezius. To hit the shoulders and rotator cuff, I do upright rows. I could throw rows in as well, but I feel I get enough from the deads and chins.