Barbara Gordon is Comissioner Gordon's adopted daughter. She becomes a protégé to Batman under the guise of 'Batgirl' and after being shot and paralysed by the joker, becomes the technological, all-knowing 'Oracle'.
The original Batgirl, Barbara Gordon was created by Gardner Fox in 1967. Since then there have four other Batgirls in the comics, none of them however have appeared outside the comics though.
Barbara Gordon was introduced in the Batman TV series during its' third season. Barbara Gordon was depicted as a librarian in this series and she wore a wig while she was batgirl and took it off when she was Barbara Gordon.
In Birds of Prey, she is portrayed by Dina Meyer. Like in the comics, she was shot during a revenge plot by the Joker, that paralysed her from the waist down. She gives up being Batgirl and becomes 'Oracle', using high-tech equipment to help Huntress and a modernised version of Black Canary fight crime and the villainous Harleen Quinzel.
In the Batman, Barbara Gordon became Batgirl to save her father, Jim when he was kidnapped by Poison Ivy. This was the first time Batgirl was introduced in a show before Robin.