A television program is a segment of content intended for broadcast on vision, other than a commercial, trailer, or any other segment of content not serving as attraction for viewership. It may be a single production, or more commonly, a series of related productions (also called a television series).
A television series that is intended to comprise a limited number of episodes may be called a miniseries or serial. Series without a fixed length are usually divided into seasons or series, yearly or semiannual sets of new episodes. While there is no defined length, US industry practice tends to favor longer seasons than those of some other countries.
A one-time broadcast may be called a "special," or particularly in the UK a "special episode." A television film ("made-for-TV movie" or "television movie"), is a film that is initially broadcast on television rather than released in theaters or direct-to-video.