Manicure/Pedicure question?

Okay so I want to know what that stuff that the manicurists spray on you is. Like you know when you go and get a manicure or a pedicure and sometimes they will have a spray can that they will spray on your nails after they're painted? Well I want to know what that stuff is called, what it does, and if anyone knows if it has parabens in it. If anyone knows what it is then please help me out here! Thanks a bunch!