Serial (radio and television)
In television and radio programming, a serial has a continuing plot that unfolds in a sequential episode-by-episode fashion. Serials typically follow main story arcs that span entire television seasons or even the full run of the series, which distinguishes them from traditional episodic television that relies on more stand-alone episodes. Worldwide, the soap opera is the most prominent form of serial dramatic programming.
Television pilot
A television pilot (also known as a pilot or a pilot episode and sometimes marketed as a tele-movie) is a standalone episode of a television series that is used to sell the show to a television network. At the time of its creation, the pilot is meant to be the testing ground to gauge whether a series will be successful; it is therefore a test episode for the intended television series, an early step in the series development, much like pilot studies serve as precursors to the start of larger activity. In the case of a successful television series, the pilot is commonly the very first episode that is aired of the particular series under its own name; the episode that gets the series "off the ground". A "back door pilot" is an episode of an existing successful series, featuring future tie-in characters of an up-and-coming television series or film. Its purpose is to introduce the characters to an audience before the creators decide on whether or not they intend to pursue a spin-off series with those characters.