Extra (acting) facts for kids
A background actor or extra is a performer in a film, television show, stage, musical, opera or ballet production, who appears in a nonspeaking or nonsinging (silent) capacity, usually in the background (for example, in an audience or busy street scene). War films and epic films often employ background actors in large numbers: some films have featured hundreds or even thousands of paid background actors as cast members (hence the term "cast of thousands"). Likewise, grand opera can involve many background actors appearing in spectacular productions.
On a film or TV set, background actors are usually referred to as "junior artist", "atmosphere", "background talent", "background performers", "background artists", "background cast members" or simply "background", while the term "extra" is rarely used. In a stage production, background actors are commonly referred to as "supernumeraries". In opera and ballet, they are called either "extras" or "supers".
Extra (acting) Facts for Kids. Kiddle Encyclopedia.