A horror film is one that seeks to elicit fear or disgust in its audience for entertainment purposes. Horror films additionally aim to evoke viewers' nightmares, revulsions and terror of the unknown or the macabre. Initially inspired by literature from authors such as Edgar Allan Poe, Bram Stoker, and Mary Shelley, horror has existed as a film genre for more than a century. Horror may also overlap with the fantasy, supernatural fiction, and thriller genres.
Plots within the horror genre often involve the intrusion of an evil force, event, or personage into the everyday world. Prevalent elements include ghosts, vampires, werewolves, evil witches, cults, black magic, demons and demonic possession, Satanism and the Devil, monsters, mummies, extraterrestrials, zombies, dystopian or apocalyptic worlds, disturbed children, gore and torture, cannibalism, natural forces, evil clowns, psychopaths and serial killers.
An example of sub-genre is psychological horror.