Horror has spawned numerous sub genre's over the course of it's life many people are aware of where as other's you may not of know exist, I shall list a few of these sub genre's below with a brief description of what they are:
Zombie Film's: Zombie films have become some what pop culture and some would argue that they are over done and exhausted. However when they first burst onto scene's thanks to director George Romero they took the film industry and audiences by storm. There are many type of zombie film some with more superhuman style zombie's other's with more shambling corpse like zombie's who are usually in mass. However the plot's tend to be some what the same with the out break of a virus that turns people into zombies and is spread by bites.
Zombie Film's: Zombie films have become some what pop culture and some would argue that they are over done and exhausted. However when they first burst onto scene's thanks to director George Romero they took the film industry and audiences by storm. There are many type of zombie film some with more superhuman style zombie's other's with more shambling corpse like zombie's who are usually in mass. However the plot's tend to be some what the same with the out break of a virus that turns people into zombies and is spread by bites.
Slasher: Slasher films proved very popular during the 80's and 90's and still are well received today, they usually rely on gore and mutilation to convey their scare's how ever some have had a darker more sinister psychological element to them to. These film much like zombie films tend to have a similar premise in which a group of teenager's either do something unruly or go off the beaten path and end up regretting it with usually only one survivor to tell the tale of the masked murder who butchered their friend's.
Sci Fi Horror: Sci fi horror began with the film invasion of the body snatchers but has evolved a lot since then has become one of the most popular genre's of horror as it gives directors a lot more creativity with premise and creatures as well as setting and characters. One film that made the sci fi horror genre so popular would be the film "Alien". Sci fi horror is one of the most diverse and versatile genres of horror has it has very few limits compared to some of the other genres, making it popular with directors. The one trend that seems to follow throughout all Sci fi horrors would be an alien or group of aliens attacking survivors either in space or on another world.
Comedy Horror: Comedy horror is the genre of horror that is not there to scary people but instead to make them laugh. Comedy horror generally tends to poke fun at horror and make a joke of some of its many cliches, some of these comedy horrors are "Scary movie" series, "Shaun of the dead" and "Haunted house" series. These films rarely have horror elements in them as they usually are flipped on there head to make it funny.
Gothic Horror: Gothic horror is perhaps one of the oldest horror genres and is one of the most iconic due to creations such as Dracula, Frankenstein monster and Werewolves which all are staple monsters in the horror genre. These horrors tend to be seen as classics and are always seen as the original horror stories and are also seen as timeless. These films tend to rely on story and atmosphere more than any of the other horror genre's.
Action Horror: Action horror is the genre of horror that is most suited to the title of action movie than horror as it is primarily action with horror elements in it opposed to the other way around. Such examples would be "World war Z" and "The Purge Anarchy" as these films are heavily action focused with few horror elements. Of all the horror sub genre's this genre relies the least on psychological and atmospheric horror.
Supernatural Horror: Super natural horror is the genre of horror that involves ghosts,spirits,demons,possessions and haunting's to scare its audience. These horror tend to be very atmospheric based and use tension to build that atmosphere. Out of all of the genres the Supernatural genre tend to be the most well received of all the genres and overall tend to be considered the scariest genre of horror with "the exorcist" leading the charge as scariest horror film as stated on many websites such as "Movie Talks".
Psychological horror: Psychological horror is the genre of horror that uses little in the line of effects and shock horror as it only subtly uses horror elements which could be seen as the most unnerving thing about it as its not so black and white as all the other horror genre's are.These types of horrors tend to use story as one of its key tools into scaring the audience as well as characters, which tend to end up being more human than the monstrous creations in the other genres as it gives a more real feel to it making it all the more horrific as the audience can relate.