A sequel is a work of art based upon another and following it in sequence. Although there can be sequels in music and art, the word is best understood and most often employed in literature and the dramatic arts, including film. In this sense, a sequel is a story that follows a previous story in dramatic, usually chronological, sequence. These normally involve characters and events from a preceding tale, although sequels may take place a long time after the original story, or may take place in roughly the same time period, but covering different themes, characters and situations.
Sequels are notorious for being considered inferior to the stories on which they are based, although in a few instances sequels have been better received or have become better known than their precursors.
A story written subsequently to another story, but in which events take place that precede those in the original story, is known as a prequel.