How do you switch between gta v story mode and gta online?

The verified evidence from Wikipedia's Development of Grand Theft Auto V article focuses on the game's development history, team size, release dates across platforms, and collaborative efforts between Rockstar studios. It confirms that GTA V is an action-adventure game developed over several years by approximately 1,000 people, with Rockstar North's core team leading development alongside other international Rockstar studios. However, this source contains no information about gameplay mechanics, specifically the process of switching between story mode and GTA Online. The evidence establishes the game's existence and development context but does not address player interface or mode-switching procedures.