Episode

An episode is a narrative unit within a larger dramatic work or documentary production, such as a series intended for radio, television or on-line consumption. 
Episode derives from the Greek term ( / "epeisodion"), meaning the material contained between two songs or odes in a Greek tragedy. It is abbreviated as "ep" ("plural" eps).
An episode is a coherent narrative unit within a larger dramatic work. It is frequently used to describe units of television or radio series that are broadcast separately in order to form one longer series. An episode is to a sequence as a chapter is to a book. Modern series episodes typically last 20 to 50 minutes in length.
Episode even can be a part of specific subject such as, episode of life or episode of drama.