Web fiction
Web serial
Fiction published in installments on the open web, chapter by chapter, as it is written.
A web serial is fiction published in installments on the open web, episode by episode, typically as it is being written rather than after completion. Serial platforms (RoyalRoad, Wattpad, Scribble Hub and their kin) host the form, and its native genres (LitRPG, cultivation, isekai) evolved inside it.
The form's defining constraints are publishing order (the audience reads chapters before any whole-book revision exists) and cadence (the schedule is part of the product). The first makes continuity tracking unusually load-bearing; the second makes release scheduling a craft skill in its own right.