Soap Opera - A soap opera is an ongoing, episodic work of fiction, usually broadcast on television or radio. They have existed as an entertainment long enough for audiences to recognize them simply by the term soap. 'Soap' refers to their origins as radio broadcasts in which various soap manufacturers were the show's sponsors. What differentiates a soap from other television drama programs is their open-ended nature. Plots run concurrently, intersect, and lead into further developments. An individual episode of a soap opera will generally switch between several different concurrent story threads that may at times interconnect and affect one another, or may run entirely independent of each other. Each episode may feature some of the show's current storylines but not always all of them. There is some rotation of both storylines and actors so any given storyline or actor will appear in some but usually not all of a week's worth of episodes. Soap operas rarely 'wrap things up' storywise, and generally avoid bringing all the current storylines to a conclusion at the same time. When one storyline ends there are always several other story threads at differing stages of development. Soap opera episodes invariably end on some sort of cliffhanger. Evening soap operas sometimes differ from this general format and are more likely to feature the entire cast in each episode, and to represent all current storylines in each episode. Additionally evening soap operas and other serials that run for only part of the year tend to bring things to a dramatic end of season cliffhanger. Some of the larger, disaster cliffhangers that affect a large proportion of the cast sometimes serve to bring all current storylines together.