In the final episode of the seven year long series, Joss Whedon makes the implicit premise of Buffy the Vampire Slayer totally explicit.
The Slayer is not a woman, but all women. All women can and should realize their full power. No woman should ever remain a doormat.
Buffy is a modern take on the woman warrior archetype. Ancient China's Hua Mulan. Medieval France's Jean D'Arc. But as most of us know, it has implications that reach far beyond physical combat, into all of our everyday lives.