Like all categories of film, horror also has sub genres that depend on the film's synopsis. Some sub genres which you may come across with horror are listed below:
Action horror contains not just supernatural elements but also gun fights. Those films usually have either zombies, demons, vampires, non-realistic animals or just gore. Some examples would be "Dawn of the Dead" or "Blade"
Body horror is based around using body limbs to create a monster. A well-known director for this type of genre is David Cronenberg. Examples of Body horror films "Cabin Fever" and "Teeth"
Comedy Horror uses comedy in the middle of death in horror fiction. Examples include the "Scary movie" series of films and "Shaun of the Dead"
Gothic horror is where Gothic themes play an important part. This genre is usually filmed in a castle or dungeon, and has a ruined landscape for the scary feeling. Examples include "Dracula", "Frankenstein and "The Mummy"
Psychological horror brings out characters' fears and guilt for the feeling, and also uses supernatural to build tension. Examples "The Shining", "The Ring" and "Exorcist"
Science fiction horror deals with the paranormal but can also include science experiments going wrong. this genre can bring out the fear of technology. Examples include "Alien" and "The Mist"
Slasher films deal with psychopathic violence- serial killers. The killer has either a specific weapon or a certain killing method. Built up on loads of mysteries and can overlap with crime. Examples include "Psycho" and "Prom Night"
Zombie Films tend to portray corpses and humans feeding off of other humans. Examples of this genre include "Night of the Living Dead" and "I am Legend"