A visual novel is a form of interactive fiction, usually Japanese, in which a story is told through text, character art, backgrounds, and music, with the reader making choices that branch the narrative into multiple routes and endings.
The visual novel is the game format closest to a book. Long passages of text, usually first person, accompany character sprites and backgrounds; music and voice acting carry scenes a novel would describe; and at intervals the reader chooses, branching the story toward different routes and endings. A single work can hold a novel's worth of text several times over, once per route.
The format produced a distinctive adaptation problem and a distinctive canon shape. An anime must pick one route or braid several, so adaptations of visual novels are interpretations by necessity, and the original's branching structure means the work itself contains multiple official versions of events. Fans of the format accept parallel routes as the medium's nature.
Visual novels sit at the edge of this site's scope: they are source material for a number of famous anime, and a subject's canon sheet records when that is the case. The glossary entry exists so that a reader meeting the term in a canon discussion knows precisely what kind of object is being cited.
In use"The anime chose one route; the visual novel it adapts contains four, all official."