An anthology series is a radio, television, or film series that spans through different genres, and presents a different story and a different set of characters in each episode, season, segment or short. These usually have a different cast in each episode, but several series in the past, such as Four Star Playhouse, employed a permanent troupe of character actors who would appear in a different drama each week. Some anthology series, such as Studio One, began on radio and then expanded to television.