bezels

Are there on the internet some illustrations available, which would show
exactly how bezel setting of a coin works? I'm no jewellery maker, so don't
know how the whole thing works, except how it looks when it's done. I heard
someone say that it's practically a locket without the front and back side,
just it's frame? If a coin is placed into a bezel, and I don't like how it
looks, is it possible to get the coin out of the bezel, without any damage
on a coin? Thanks!

Marijan