A horror film is one that attempts to evoke feelings of dread or disgust in its viewers in order to provide entertainment. In addition, horror films are intended to elicit nightmares, revulsions, and fear of the unknown or the macabre in its viewers. Horror has existed as a cinema genre for more than a century, having been influenced by writers such as Edgar Allan Poe, Bram Stoker, and Mary Shelley as well as other works of literature. Horror may also have crossovers with other genres such as fantasy, supernatural fiction, and thrillers.
Horror stories often revolve on the introduction of a terrifying force, event, or person into the ordinary world. Other elements that appear often in horror films include ghosts, vampires, werewolves, evil witches, cults, black magic, demons and demonic possession, Satanism and the Devil, monsters, mummies, aliens, zombies, dystopian or apocalyptic worlds, disturbed children, blood and torture, cannibalism, natural forces, evil clowns, psychopaths, and serial killers, to name a few.