Batman is the super-hero protector of Gotham City, a man dressed like a bat who fights against evil and strikes terror into the hearts of criminals everywhere. In his secret identity, he assumes the alias of Bruce Wayne, billionaire industrialist and notorious playboy; though "Bruce Wayne" is technically his real name, this Bruce Wayne is a disguise--that of the man he would have been had his parents not been murdered before his eyes when he was no more than a mere boy.
Although Batman possesses no super-human powers, he is one of the world's smartest men and greatest fighters. His physical prowess and technical ingenuity make him an incredibly dangerous opponent. He is also a founding member of the Justice League and the Outsiders. Dick Grayson, the first "crime orphan" to assume the identity of Robin and be nicknamed "The Boy Wonder," who currently uses the alias of Nightwing, is Wayne's hand-picked successor, and they operate simultaneously as part of Batman Incorporated.
The Joker, an insane arch-criminal, is Batman's greatest enemy, on a diabolical quest to drive all of society as cacklingly mad--as laughingly insane--as he himself is; unfortunately for these evil plans of the Joker's, however, Batman repeatedly refuses to acknowledge any sense of humor within himself and sees himself as a guardian of not only logic and reason, but also sanity and seriousness.