Genres
Light novel
A Japanese publishing format: young-adult novels with manga-style illustrations, issued in the compact bunkobon size and often adapted into anime.
A light novel (raito noberu, often shortened to ranobe or LN) is a style of Japanese young-adult fiction typically featuring manga-style illustrations, often black and white. The format is commercial as much as textual: books are published in the compact bunkobon size as low-priced paperbacks, on dense schedules that bring a new installment every three to nine months. Many chapters are first serialized in magazines or posted as web novels, then collected into book form, and hits are routinely adapted into manga, anime, games and live-action film.
The label matters to web-serial writers because it names a print publishing format, not a genre or a birthplace: the same story can start as a web serial and be collected as a light novel. See the publishing paths those two tracks lead to.