Supernatural Horror:
One of the most common horror genres. These stories often use ghosts, demons, vampires, werewolves, the occult and other beings from folklore or legend to incite fear in the audience.

Biological/Body horror
A type of horror in which the horror is principally derived from the graphic destruction or degeneration of the body. Such works may deal with disease, decay, parasitism, mutilation, or mutation.

Gothic Horror:
It is a form of horror storytelling in which the environment and setting is an important feature within the story, often using the setting to create an overall sense of dread or foreboding. It is usually based on European literature in which it combines elements of both horror and romance.

Gore/Splatter Horror:
It's a genre in which the human body itself is used as the primary device by which the audience is confronted with the horrific. These stories can include transformation or mutilation to the body as a way to reflect an innate fear of death or loss of control. It goes straight to the blood-and-guts and aims for the gross-out without hesitation. In guidelines you might find terms like "splat," "splatter," or "splatterpunk" and "gore," "grue," and "gross."

Lovecraftian Horror:
As long as you have some idea of who H.P. Lovecraft was and what he wrote, these probably make sense. Lovecraft's fictional premise was that the world was once inhabited by another race of dark powers. Although cast out, they live on somewhere always ready to take the world back. "Lovecraft style" is florid and never stints on adjectives.

Noir:
Usually set in an urban underworld of crime and moral ambiguity. Dark, cynical, paranoid themes of corruption, alienation, lust, obsession, violence, revenge and the difficulty of finding redemption in a far from perfect world. An oppressive atmosphere of menace, pessimism, anxiety, suspicion, and dingy realism. You'll also find the term in combinations like neo-noir, future noir or noir sf, tech-noir.

Psychological Horror:
Based on the disturbed human psyche in which the action or concepts that are unpleasant within the story are largely psychological in nature, often dealing with insanity and common fears among people. Obviously psychos on rampages fall into this category, but it is just as often more subtle. Since the reader's perception is sometimes altered by exposure to an insane viewpoint, psychological horror can also deal with ambiguous reality and seem to be supernatural.

Quiet/Soft Horror:
Subtle, never visceral or too shocking, with atmosphere and mood providing the miasma of fear rather than graphic description.

Surreal/Abstract Horror:
Not really sub-generic, it can be used just to mean unreal; strange or bizarre. Or it can be used to tie a style to the surrealist movement in art and literature that attempted to express the subconscious and move beyond accepted conventions of reality by representing the irrational imagery of dreams and bizarre juxtapositions.

Suspense/Thriller/Mystery:
No supernatural elements, but a constant sense of threat coming from an outside menace. Add a strong investigative angle and becomes mystery more than horror. Add action and adventure to suspense and you come up with "thriller" -- except you can have "supernatural thrillers."

Sci-fi/Extraterrestrial Horror:
Sci-fi horror films are a sub-genre of science fiction and horror films, often revolving around subjects that include but are not limited to alien invasions, mad scientists, and/or experiments gone wrong. It typically uses elements from far outside humanity to introduce horrific concepts, often reflecting humanity’s insignificant role within the larger cosmos.

Erotic Horror:
Usually "erotic" means sensual sexual content integral to the story and can be as mild as "romantic suspense." Many editors and writers prefer the term "sexual horror" over erotic, as the sex in horror can be far from nice or arousing. "Erotic" can be stretched to mean graphic, intentionally explicit sex in a story meant for a pornographic market. The code word being "explicit."

Dark Fantasy/Dark Fairy Tale:
It is a term used to describe a fantasy story or fairy tale with a pronounced horror element.

Survival Horror:
It is a relatively new form of horror, or at least the name for it is fairly new. In this type of horror, the struggle to survive against a harsh environment is often the backdrop against which the line between human and inhuman action is drawn, using disastrous situations to reflect on the nature of the human race and what people are capable of doing to survive.