How do gta v online missions differ from story mode?

Grand Theft Auto Online operates as a separate multiplayer experience from GTA V's story mode, supporting up to 30 players simultaneously compared to the single-player narrative focus. While both share the same fictional San Andreas setting and Los Santos city, Online missions emphasize cooperative heists, competitive modes, and player-driven activities rather than the linear story campaign. Online introduced new mission types like VIP work, races, and adversary modes that don't exist in story mode, and features a persistent world where player actions and progress persist across sessions. Story mode follows the predetermined narrative of three protagonists, while Online allows players to create custom characters and engage in evolving content through regular updates.