In fiction, canon is the material accepted as officially part of the story in an individual universe of that story by its fan base. It is often contrasted with, or used as the basis for, works of fan fiction. The alternative terms mythology, timeline, universe and continuity are often used, with the first of these being used especially to refer to a richly detailed fictional canon requiring a large degree of suspension of disbelief (e.g. an entire imaginary world and history), while the latter two typically refer to a single arc where all events are directly connected chronologically. Other times, the word can mean "to be acknowledged by the creator(s)".