If you have an iPhone, the bezels are the part of the phone that are around the actual screen of the phone. Smaller bezels make for a smaller phone frame, which makes it easier to hold etc.
2015girl, a bezel is nothing more than a fancy name for frame. So talking about the iPhones bezel or a bezel on a TV etc. is talking about its frame, the plastic or metal piece around the screen.
I was (admittedly somewhat dickishly) suggesting that you can literally type 'bezel' the search bar, and you'll get the definition as the first result.
2015girl, a bezel is nothing more than a fancy name for frame. So talking about the iPhones bezel or a bezel on a TV etc. is talking about its frame, the plastic or metal piece around the screen.