Most people use screen protectors on their devices.. Most of these screen protectors are of the cheaper quality (plastic, flimsy ones). They still work great for minor scratches, fingerprints, etc. But they do not offer actual protection for your screen.
If you're looking for a screen protector that will actually offer some protection (drop protection), take a look at some tempered glass screen protectors. I'm using one on my Sony Xperia Z2 is made by Gearmaxx. There's plenty of other brands that probably offer the same protection, but I highly recommend Tempered Glass over the plastic screen protectors.
If you look online at some test videos, what is supposed to happen with a tempered glass screen protector is when you drop the phone on the screen, the tempered glass shatters and absorbs the impact. Since it has a very light glue on it, the shattered glass sticks to your screen. You simply peel off the shattered screen protector, and your screen will still be perfectly okay. Keep in mind this works for drops. This does not mean you can bring a sledge hammer to your screen and expect it to work.
I was skeptical at first when I saw the price of tempered glass protectors vs the plastic ones. But after using one first hand, I'm sold on them. I will never buy a plastic screen protector again for my phone. Tempered glass for the win.