Reality television is a genre of television programming that documents supposedly unscripted real-life situations, and often features an otherwise unknown cast of individuals who are typically not professional actors, although in some shows celebrities may participate. It differs from documentary television in that the focus tends to be on drama, personal conflict, and entertainment rather than educating viewers. An early term for the format was docu-soap. The genre has various standard tropes, including “confessionals” (also called talking heads or interview segments) used by cast members to express their thoughts, which often double as the shows’ narration. In competition-based reality shows, a notable subset, there are other common elements such as one participant being eliminated per episode, a panel of judges, and the concept of “immunity from elimination.”