Batgirl is Barbara Gordon, at least the way I've always understood it.
The Barbara Gordon version of Batgirl made regular appearances in Batman-related comics from 1966–1988 and is described as one of the most high profile characters to be published during the Silver Age of Comic Books. Following the editorial retirement of the character in Batgirl Special #1 (1988), Barbara Gordon is paralyzed by The Joker in the graphic novel Batman: The Killing Joke (1988). Editor Kim Yale and comic book author John Ostrander later reinvented Barbara Gordon as Oracle, the premiere information broker of the DC Comics Universe and leader of the Birds of Prey organization.