Original: Several years before Angel debuted, Joss Whedon developed the concept behind Buffy the Vampire Slayer to invert the Hollywood formula of "the little blonde girl who goes into a dark alley and gets killed in every horror movie."
Simplified: Several years before the Angel first showed on television, writer Joss Whedon created the idea behind Buffy the Vampire Slayer to change the Hollywood formula of "the little blonde girl who goes into a dark alley and gets killed in every horror movie."