Let me clear this out of the way early on: if you're wondering which I recommend, my answer is it depends on your goals. Bent-over rows, unlike deadlifts, are a back specific exercise, particularly upper back. Yep, there are a lot of different ways to perform rows but ultimately, their sole focus is your back.
Deadlifts, whilst they also target the back, incorporate and impact a far broader range of musculature than rows and thus, are less back specific in my opine. You'll have heard the term "posterior chain", a fancy phrase for the musculature at the rear of the body -- think back, butt, hamstrings, calves -- which is something deadlifts hit hard.
Rows don't.
So if you want a back-specific movement, stick with bent-over rows. If you want to develop over-all musculature and strength with a focus primarily on the posterior chain, stick with deadlifts. But. Like every netspurt espouses (this time including me), using both makes sense so as to hit back completely, competently and confidently.
...that there's three-Cs and therefore, most holy.
Oh, but you don't have to. It really is up to you, kemosabe.
WHAT MUSCLES DO ROWS HIT?
Bent-over rows target the lats, traps, rhomboids, infraspinatus, teres minor & major and rear delts -- basically your entire upper back. If there are any other fuckers in there trust me, they're getting it too. They target your core which holds you in place, specifically the erectus spinae, and your neck and biceps (you are hauling shit up with your arms after all).
Sure, the lower back, hamstrings and forearms play a role but let's call a spade a spade: bent-over rows hammer the shit out of your back. See why I label them back-specific? Their sole aim is the back. Anything else is just an added benefit, a result from spill-over. Rows are literally a compound movement that isolates the back, if that even makes sense.
ARE THERE DIFFERENT WAYS TO ROW?
Yes. Yes there are.
Am I going to go into those? No, no I'm not.
Just don't fall over yourself reading cajillions of online articles about the "correct way" to do rows. Do cable-rows, T-bar rows, dumbbell rows whatever: they all work. Do 1-armed rows, barbell rows, Pendlay rows or the Yates row: they all work too. Do them at 45°, 75° or naked with your ass to the window: I understand those work magnificently.
Get the point?
Yeah, the less angle you use the more a row becomes an incline shrug but y'know what? Even when incline shrugging you still use your upper back so don't sweat the small stuff. Tuck your elbows, flare your elbows, use a narrow grip, use a wide-grip, use straps, don't use straps, wear loose shorts or those lycra mumblers just fucking row.
WHAT MUSCLES DO DEADLIFTS HIT?
Deadlifts hit your lats, traps, rear delts, levator scapulae, splenius, rhomboids, neck, erector spinae, glutes -- and every muscle through-out the entire hip region -- hamstrings, calves, abdominals & obliques, forearms, quads and let's be honest: they pretty much drag in every other muscles group on the human body on top of.
They are the penultimate all-rounder, one of the best if not THE best 1-off exercises that trains the entire body. In the words of Staff Sargeant Barnes from Platoon: "I shit thee not". What's more, I didn't even know what some of the above were I mean, a splenius? Has anyone ever heard of that? Sounds a food order at an Italian restaurant.
...any 'ol who.
ARE THERE DIFFERENT WAYS TO DEADLIFT?
Yes. Yes there are.
Am I going to go into those? No, no I'm not.
...deja vu anyone?
But. Just like with bent-over rows whether you sumo deadlift, stiff-legged deadlift, Romanian deadlift or Canadian deadlift (this is where you're naked but doused with roofing glue to which your significant other slaps maple leaves while you deadlift), use a barbell, dumbbells, trap-bar or your nephews fat girlfriend, know they all work. I think.
Again, don't over think it. Don't get caught up searching for the sacred answer as to whether deadlifts are the be-all and end-all because they're not. They're just an exercise, mate. Yes, they're a very effective exercise but the truth is you don't have to deadlift. Many of our bodybuilding kin have developed phenomenal physiques without a deadlift in sight.
:: CONCLUSION
Bent-over rows and deadlifts do target similar parts of the back, but how they do so differs. With a row you're pulling to the torso; that's the sole movement and your back musculature -- primarily the upper back, though it should be pointed out the erectus spinae are supporting and stabilizing you in the movement -- takes the maximum strain.
That's what you work the most and that's where you feel it most.
Simple.
Deadlifts on the other hand necessitate a wider range of body parts to facilitate the lift, all of which must work in conjuction, and all of which require energy. In my opinion this energy-dispersion across a broader range of musculature reduces focus on the back as so many other body parts come into play for maximum effort.
Remember, deadlift isn't just lifting a barbell from a dead stop it's also hinging forward as you clear the knees -- literally thrusting your pelvis into the bar -- whilst continuing to straighten till fully upright. With rows you simply hold an angle and pull to the torso. You can control the eccentric, focus on the stretch, pinch the shoulder-blades and incorporate time under tension.
...none of which you can do with a deadlift.
With bent-over rows the energy is focused in a much narrower range of motion across a much narrower range of musculature. You not only have more energy to draw upon, you can leverage the weight better and focus on actual back musculature -- whilst with a deadlift your whole body is screaming.
Further more, bent-over rows are easier to perform and easier to perform more regularly, which makes them more effective in the long-term as well (for hypertrophy purposes at least). Yes, heavy deadlifts will make you mule-strong but heavy rows are by no means a secondary cousin, least of all if you want a more back-specific focus.
That's my 10c worth anyway. Hope it helps. Kia ora whanau.