A sitcom, short for "situation comedy", is a genre of comedy centered on a fixed set of characters who carry over from episode to episode. Sitcoms can be contrasted with sketch comedy, where a troupe may use new characters in each sketch, and stand-up comedy, where a comedian tells jokes and stories to an audience. Sitcoms originated in radio, but today are found mostly on television as one of its dominant narrative forms. This form can also include mockumentaries.
A situation comedy television program may be recorded in front of a studio audience, depending on the program's production format. The effect of a live studio audience can be imitated or enhanced by the use of a laugh track. During filming productions, the laugh track is usually prerecorded.
The terms "situational comedy" or "sitcom" were not commonly used until the 1950s. There were prior examples on radio, but the first television sitcom is said to be Pinwright's Progress, ten episodes being broadcast on the BBC in the United Kingdom between 1946 and 1947. In the United States, director and producer William Asher has been credited with being the "man who invented the sitcom", having directed over two dozen of the leading sitcoms, including I Love Lucy, from the 1950s through the 1970s.