If you understand nothing else from the following words, understand that roleplaying games are games . The point of them, as with any game, is to have fun, and everything else is secondary.
T hat having been said, a roleplaying game is somewhat different than other kinds of games.
In a way it's like improvisational acting, in that each player has a character, not himself, and he acts, to a certain extent, as if he is that character. In the most common kind of roleplaying, tabletop, the kind with dice and sheets of paper, this acting is limited to words. In Live Action, both words and movements are used, but the combat is fake, with fake weapons, as are many other aspects. What separates those games from roleplaying is the rules we use. Different systems have varying degrees of sucess at this.