Oracle is Barbara Gordon, who was once Batgirl. She was shot by the Joker, and now she is wheelchair bound. Even though her name is “Oracle” is not psychic. I guess she can hack into computers, but I have no idea what her name has to do with her superpowers.
Oracle runs the Birds of Prey, which is home to the wayward and forgotten female superheroes and sidekicks of Gotham City. I heard Power Girl was part of the team for an issue or two, but she left because couldn’t do the double toe touch during the auditions and kept dropping her pompoms.