What makes a horror film?

A horror film has the audience on edge throughout, scared of what is going to happen next. It needs to have a main character that the audience will be afraid of seeing when it appears on screen, this can be human or creature. It has to have the audience guessing, cant be too obvious. The setting of the film must have a spooky feel to it otherwise the audience wont be scared of it. I think that having scary music over the back, like the music on my blog, when something is about to happen can increase the fear in the audience.