Horror is frequently supernatural, though it might also be non-supernatural. Often the central menace of a work of horror fiction can be interpreted as a metaphor for the larger fears of a society. A horror film is one that seeks to elicit fear in its audience, for entertainment purposes. The macabre and the supernatural are frequent themes. Horror may also overlap with the fantasy, supernatural fiction, and thriller genres.
Horror films often aim to evoke viewers' nightmares, fears, revulsions and terror of the unknown. Plots within the horror genre often involve the intrusion of an evil force, event, or personage into the everyday world. Prevalent elements include ghosts, extraterrestrials, vampires, werewolves, demons, Satanism, evil clowns, gore, torture, vicious animals, evil witches, monsters, giant monsters, zombies, cannibalism, psychopaths, natural, ecological or man-made disasters, and serial killers.
An example of sub-genre is psychological horror.