Power Girl, also known as Kara Zor-L, Karen Starr and Paige, is a superheroine appearing in American comic books by DC Comics, making her first appearance in All Star Comics #58 (January/February 1976). Power Girl is the cousin of the superhero Superman, but from an alternate universe in the fictional multiverse in which DC Comics stories are set. Originally hailing from the world of Earth-Two, first envisioned as the home of DC's wartime heroes as published in 1940s comic books, Power Girl becomes stranded in the main universe where DC stories are set, and becomes acquainted with that world's Superman and her own counterpart, Supergirl.
In common with Supergirl's origin story, she is the daughter of Superman's aunt and uncle and a native of the planet Krypton. The infant Power Girl's parents enabled her to escape the destruction of her home planet by placing her in a rocket ship. Although she left the planet at the same time that Superman did, her ship took much longer to reach Earth-Two. On Earth, as with other Kryptonians, Power Girl discovered she possessed abilities like super strength, flight, and heat vision, using which she became a protector of innocents and a hero for humanity. Though the specifics of how vary over subsequent retellings, Power Girl is later stranded on another Earth when a cosmic crisis affects her home of Earth-Two, and later carves out a separate identity for herself from her dimensional counterpart Supergirl once they are forced to coexist.
Though they are biologically the same person, Power Girl behaves as an older, more mature, and more level-headed version of Supergirl, with a more aggressive fighting style. She also adopts a different secret identity from her counterpart. These changes are reflected in their differing costumes and superhero names as well; Power Girl sports a bob of blond hair; wears a distinctive white, red, and blue costume with a cleavage-displaying cutout. The name Power Girl reflects that she chooses not to be seen as a derivative of Superman, but rather her own hero and this choice is reflected in the strong independent attitude of the character.