Is gta online a standalone game or an expansion of gta v?

Grand Theft Auto Online was released as the online multiplayer component of Grand Theft Auto V. Developed by Rockstar North and published by Rockstar Games, it launched on 1 October 2013 for PlayStation 3 and Xbox 360, with later releases on PlayStation 4, Xbox One, Windows, and the PlayStation 5 and Xbox Series X/S. The game operates within the same open‑world setting as GTA V, the fictional state of San Andreas, and allows up to thirty players to explore the environment, partake in cooperative or competitive missions, and engage in various game modes. Unlike a standalone title, GTA Online requires the base game, GTA V, to be installed and is intended to extend the life of the original game rather than replace it. The online component can be accessed without purchasing a separate version of the game, but it relies on the core assets and map provided by GTA V.