The rind is the outer layer of, typically, a wheel of cheese. It's there to protect the cheese from the elements, which allows the cheese to safely continue maturing. It also imparts a unique flavour to the cheese, and plays a role in the final texture.
Let's get to what matters though—can we eat it?
Mostly, yes! It generally depends on the type of rind you've got and what you like to eat.
Hard rinds made of wax or cloth are probably best discarded, because their primary purpose is cheese protection, and aren't ideal for digestion.
Natural rinds can be used for their umami flavour. Use them to thicken and add a special touch to broths and soups. Sure, you can eat these, but your jaw will have its work cut out getting through that tough exterior.
Washed rinds, are somewhere in between the natural and bloomy rinds. Some may have a coarse and waxy-looking exterior, but if they're thin enough, and you like their taste, go forth and monch.
Flavoured, and bloomy rinds, however, pretty much invite you to eat them, as they're part of the cheese experience. Get involved!