A sketch comedy consists of a series of short comedy scenes or vignettes, called "sketches," commonly between one and ten minutes long. Such sketches are performed by a group of comic actors or comedians, either on stage or through an audio and/or visual medium such as broadcasting. Often sketches are first improvised by the actors and written down based on the outcome of these improv sessions; however, improvisation is not necessarily involved in all sketch comedy.

An individual sketch or vignette is a brief scene or skit formerly used in vaudeville and used today on variety shows, comedy programs, adult entertainment, talk shows, or certain children's television series (such as Sesame Street). Such a sketch can include footage of a "man on the street", pioneered by American television personality Steve Allen on evening comedy television programs like The Tonight Show.

More serious sketch comedians differentiate their art from that of the skit, maintaining that skits tend to be a (single) dramatized joke, while a sketch is a comedic exploration of a concept, character, or situation.