In another sense, a canon is a list of books accepted as authoritative or divinely inspired by a religion. The term was originally Christian, referring to books declared divinely inspired by the canons of Church councils. The term has however come to be extended to other religions as well with compound scriptures, thus one can speak for instance of the Pali canon in Buddhism. See biblical canon for a discussion of the canon of Christianity.
In literature and art
In non-academic, non-religious contexts, canon is used to describe works of fiction that represent "official" records of events in particular fictional settings. For example, in Star Trek, the various live-action television series and movies are considered to be canon whereas the Star Trek novels and cartoon series are not. Events which occur in non-canon works of fiction are not considered a part of the continuity of the rest of the series, and can be disregarded freely by authors and readers alike when considering the setting as a whole. The criteria for deciding whether a particular work of fiction is considered to be canonical for a particular setting or not varies, sometimes being dictated by a particular authority and sometimes being decided by informal consensus among those who care.