What progression systems exist in grand theft auto v story mode?

The verified evidence describes Grand Theft Auto Online, the multiplayer component of Grand Theft Auto V, highlighting its features like open-world exploration, player customization, and cooperative or competitive game modes. However, the evidence does not address the story mode of Grand Theft Auto V, which is the single-player campaign featuring three protagonists. Since the source material is limited to information about GTA Online, no details about progression systems in the story mode can be confirmed or explained based on the provided evidence.