A fake ID generally mimics an original ID issued by organizations or legislative bodies, like your government. The purpose of a real ID is to serve as identification for employees and citizens and, in the case of government-issued IDs, to hamper criminal activity and nights of fun for hardworking students who want nothing else but a few hours of relaxation and fun.
On the surface, a fake ID is just a chunk of plastic with your name, picture, and a bunch of other details. Well, that’s probably the answer you will get to hear if you ask an adult about it. But ask someone who has been less fortunate in the age department so far, and they will tell you a different story.