Sketch comedy comprises a series of short, amusing scenes or vignettes, called "sketches", commonly between one and ten minutes long, performed by a group of comic actors or comedians. The form developed and became popular in vaudeville, and is used widely in variety shows, comedy talk shows, and some sitcoms and children's television series. The sketches may be improvised live by the performers, developed through improvisation before public performance, or scripted and rehearsed in advance like a play. Sketch comedians routinely differentiate their work from a “skit", maintaining that a skit is a (single) dramatized joke (or "bit") while a sketch is a comedic exploration of a concept, character, or situation.[citation needed] Sketch comedy is a genre within American television that includes a multitude of schemes and identities.