At the core of the show is a Jungian investigation of archetypal symbolism, the importance of dreams and symbols as links to a collective unconscious, a place where gods and monsters are real.

if that kind of description floats your boat, you can read the rest of the article at popmatters. the link is actually better for all the other buffy articles on it, the one claiming that the death of tara was homophobic notwithstanding.