Horror films seek to elicit fright, dread and alarm from viewers. This is achieved through various techniques such as fast, startling cuts and sounds, shadows and darkness, frequent controversial violence and gore, and alternating shock and suspense. Frequent subject matter include the macabre, the supernatural/occult, nightmares, fear of the unknown, and the darkness at the heart of man.
Horror films go back almost as far as film itself but the roots of horror began in folk tales, ghost stories, and the writings of Mary Shelley, Bram Stoker and Edgar Allan Poe. In a similar fashion to fairy tales, horror themes are often representative of deeper cultural/social/political fears and tend to intrinsically push a conservative sense of morality. Characters who partake in drink, drugs, sex or even display antisocial tendencies rarely survive the outcome of the film. This morality is in stark contrast to the violent and amoral content of the films. A happy ending is nigh on impossible with even the most satisfying resolution usually followed by the villains return (which immortalises the dread and encourages a sequel).
Visual iconography is a large part of horrors style, especially with regard to the films villainous entity. The mask, weapon, and/or costuming choice for this character frequently becomes the identifying visual symbol for the film or film series (more so than any victims of their wrath who are interchangeable at best or disposable at worst). Indeed many horror villains are instantly recognisable even by those who have never seen the source material.
Beginning with Scream (1996) many horror films now exist in a post-horror world. Characters now behave as though they are familiar with the tropes and clichés of horror films. This can bring realism, or by contrast a self-awareness that borders on the painful or comic to films.
Bibliography:
FilmmakerIQ.com, “A Brief History of Horror” – http://filmmakeriq.com/lessons/a-brief-history-of-horror/
Dirks, Tim, “Horror Films” – http://www.filmsite.org/horrorfilms.html
The Script Lab, “Horror” – http://thescriptlab.com/screenplay/genre/horror
Wilson, Karina 2001-2013, “Horror Films: Why We Like to Watch” – http://www.horrorfilmhistory.com/
Dawson, M 2008-2009, “Analysis: Horror Movies as Modern Day Morality Tales” – http://www.leftfieldcinema.com/analysis-horror-movies-as-modern-day-morality-tales-%E2%80%93-introduction