What are the main differences between gta online and gta v story mode?

The available Wikipedia evidence discusses Grand Theft Auto V's development, including its 1,000-person team, release timeline across multiple platforms, and its status as a spiritual successor to previous Rockstar titles. However, it does not address gameplay modes, online features, or comparisons between story mode and GTA Online. Without explicit details about these aspects in the source material, I cannot accurately describe their differences.