Comedy is a film genre that uses humor to elicit laughter from audiences through entertaining stories and characters, though some comedies address serious topics; most have happy endings. Comedies often blend with other genres, like romance or horror, creating sub-genres like romantic comedies or parody films. Successful comedies frequently depend on popular individual stars to draw audiences.

1. Comedy genre.
Comedy is a genre of film that uses humor as a driving force. The
aim of a comedy film is to illicit laughter from the audience
through entertaining stories and characters. Although the comedy
film may take on some serious material, most have a happy
ending. Comedy film has the tendency to become a hybrid sub-genre
because humor can be incorporated into many other genres.
Comedies are more likely than other films to fall back on the
success and popularity of an individual star.
(Source; script Lab.
http://thescriptlab.com/screenplay/genre/comedy)
Sub/ hybrid genres.
Comedies can be involved in many different types of move genres
for example: rom-coms are a mix of romance and comedy movies
whilst you can also get movies that have a hint of comedy and
horror which are normally named as spoof movies or parodies.
In these sub genres you will normally have a build up of romance
or maybe horror then a sudden outbreak of comedy.
Key comedy movies.
Hangover, Shrek, Toy story, ghost busters, rush hour, Ghostbusters.