An episode is to television and radio what a chapter is to a book: a part of a sequence of a body of work. The term sometimes applies to works based on other forms of mass media as well, as in Star Wars. Episodes of news programs are also known as editions.
Episodes which end in the middle of a climatic moment are often called cliffhangers, after the name used for early movie serials. Such episodes can be nearly daily occurrences in soap operas and are frequently used in season finales of many prime time shows.
Episodes can be part of a larger story arc stretched out over a time period covering one or more seasons, or even an entire series run. This is true for some science fiction series such as Babylon 5 and Star Trek.
Episodes often have their own titles; each episode of Friends, for example, had titles which began "The One ...", such as:
- "The One Where Ross and Rachel Take A Break"
- "The One After the Super Bowl"
- "The One with the Princess Leia Fantasy"
Show also have numbers or codes for each episode. The X-Files, for example, assigned a code in the format "sXnn", with 's' identifying the season number and 'nn' being a two-digit number for each show, starting with '01'. Some programs, such as The Simpsons, use numbering systems that are hard for anyone outside the production company to understand. Template:Tv-stub