Genre

The term genre is used a lot around the movie industry to break down the type of film into categories. It's difficult to place a lot of films in a single category. For this reason a lot of films have multiple genres. New movies are created daily and there is always reference to other script, author, director or a book. Made recognisable intentionally as intertextuality or due to inspiration from the reference's creator. This is why a movie can never be "categorised" enough. There will always be something that doesn't match the genre. But based on the main elements, movies are categorised accordingly so they can suit the needs of search engines and movie databases. I think this is due to the fact that movie's storyboards now-a-days are a reflection of the audience's desires. With easy access to media everywhere (internet, television, adverts, etc.) , the viewer's knowledge has increased drastically, leading to increased interest in detail. The audience will always search for some hidden joke signified by another interesting tabloid title or for similarity with another movie. This is mostly seen in teenage series like "Family Guy", "South Park", "The Simpsons" and etc. On the other hand, in full-lenght movies, the audience will look for realism in horror and thrillers, or for logic in sci-fi. Let's analyse these two genres. 

HORROR and THRILLER (not the Michael Jackson one)

Nightmare On Elm Street (1984)

Director: 

Wes Craven

Writer: 

Wes Craven

Stars:

 Heather Langenkamp, Johnny Depp and Robert Englund

Now that's what I'm talking about. When I say horror and realistic, I mean that. Modern CGI effects are good, but still not good enough so they can full the human's curious eye. 3D objects are too noticeable and the reactions are too predictable. Old school effects is what should have been enhanced. Every modern eye can see this movie and say "oh my God, this was scary".  These original effects combined with lighting, depressing music, narrow halls and tiny rooms, this is what the magic was.