Back is about knowing your angles
 

The horizontal row is a staple exercise in many back workouts. This is for good reason. Horizontal row variations train the majority of your back musculature like the lats, rhomboids, traps, rear deltoids, etc. Depending on how you perform the row, you can place more focus on different areas of your back.
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If you want to focus more on training the lats and mostly the lower portion of your lats, it's a good idea to do close-grip rows in which you pull your elbows towards your lower abdominal area. As you can see if you swipe left on the picture, the resistance runs more in line with the lower area of your lats when you use a close-grip v-bar attachment.
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If you want to focus more on training the upper back, you can benefit from doing wide-grip rows in which you pull the bar towards your upper abdominal/lower chest area. This will ensure the resistance in more in line with the muscles in your upper back (e.g. rhomboids, mid/upper traps, rear delts).
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Keep in mind that these are minor details, a row will train pretty much your entire back. But these details are useful to know if you are looking to work on specific areas of your back!