Apocalyptic horror - this is basically what I write. I write in a sub-genre of apocalyptic horror, the zombie apocalypse. There is also nuclear apocalypse, virus apocalypse, apocalypse brought on by war, animal apocalypse (there's a great book titled MORT by Robert Repino about a cat run apocalypse, it does have some hard to read scenes, but it is so good). Zombie horror in itself varies. There is horror from the zombie point of view (the Monster Island series and my series both have zombies as main characters), zombie horror that is dark comedy (WARM BODIES), and zombie horror that is very close to the movie NIGHT OF THE LIVING DEAD. When people ask what I write, I often say zombie novels, because that is a simple answer, but in reality I write apocalyptic horror with a strong zombie story. My novels aren't about the zombies, they are about the way we segregate those who are different. Honestly, if an apocalyptic novel is well written, it usually isn't about the apocalypse, but the way humans react to the apocalypse. Do they tear each other down? Kill because they can? Rape because they can? Build societies they believe to be prefect utopias? Nothing is ever as they seem really.
Ghost Horror - this isn't always your typical haunted house book, although those are ghost horror. This genre can range from a haunted house to Simon R. Greens "Ghost Hunter" Series, even Emily Bronte's WUTHERING HEIGHTS can be considered ghost horror. There are some issues with ghost horror these days as ghost (much like vampires and werewolves) are being used in other genres as romantic devices, which I don't necessarily approve of, but I still read the Sookie Stackhouse series by Charlaine Harris. I try to keep up with pop culture and new trends so that I know what is out there and where horror is going. Ghost horror can be anything from a haunted house to a woman who works in a boys home, but who is really dead herself. It can be written from a scared woman's point of view, or it can be written from the ghosts point of view. It can be all about finding the murderer, or it can be about making sure the people left behind after your death stay alive and find happiness. Why are so many attracted to ghost horror? Because no one is sure what, or if, the afterlife may be like.
Extreme horror - this is a horror that involves a lot of gore, language, violence, and often revenge. This horror is found in movies like SAW and several books by Ray Garton and Edward Lee. Extreme horror is not for everyone as it often is very graphic and can be disturbing. For example, in THE CELLAR by Ray Garton he graphically writes about the rape of a child, and again this is not for everyone, in fact there may be a small underground love of these books as some readers do this behind closed doors and often do not share that they read this type of horror. I have read several of Edward Lee's novels and while I love his "Infernal Angel" series his novel FLESH GOTHIC was a little much for me as it involved lots of sex, body mutilation, and debauchery. This horror is for those who like the adrenaline rush of finding out if the girl who was raped and left for dead gets her revenge, in the most violent way possible.
These are a few of the genres that I wanted to explain a little bit about. Often zombie novels are compared to extreme horror because they involve body horror (decomposing bodies described in graphic detail as they wander across the earth). Zombie novels can be extreme horror, and they can be body horror, just because a book fits in once genre or sub-genre of horror doesn't mean that it won't also fit in another. Genres are fluid and they are ever evolving. What is a straight-forward genre today, might actually be a a sub-genre of something else in the future.