Horror films effectively center on the dark side of life, the forbidden, and strange and alarming events. They deal with our most primal nature and its fears: our nightmares, our vulnerability, our alienation, our revulsions, our terror of the unknown, our fear of death and dismemberment, loss of identity, or fear of sexuality.
Whatever dark, primitive, and revolting traits that simultaneously attract and repel us are featured in the horror genre. Horror films are often combined with science fiction when the menace or monster is related to a corruption of technology, or when Earth is threatened by aliens. The fantasy and supernatural film genres are not synonymous with the horror genre, although thriller films may have some relation when they focus on the revolting and horrible acts of the killer/madman.
