Marvel is one of the biggest producers of superhero media in the world. Starting out in comic books, Marvel has branched out into telivision, movies, video game and more types of media. Through their early start, their hundreds of characters, and unique stories, Marvel has become one of the genre definers for the superhero genre. One of the things that makes Marvel so popular are their superheroes, and in turn their superhero teams. The most popular and well known of these teams include the Avengers, the X-Men, and the Fantastic Four who have been with Marvel for almost as long as Marvel has existed and have helped not only set Marvel as a definer of the superhero genre, but have also help expand the world that Marvel takes place in.