As we know that there are Three different playable Protagonists in-game, they are Michael De Santa, Franklin Clinton, and Trevor Phillips. They have their own special abilities, issues, problems, lifestyles, desires, goals, and objectives.
Michael De Santa
Michael is a veteran bank robber, and he's an expert in this particular field and has many more criminal charges. Michael is a successful bank robber who made his own lifestyle in Los Santos and now he's retired and living comfortably. He has a wife, 2 children Son, and a Daughter. He has everything he wanted, but still, he's miserable.
Franklin is the street gangster in Los Santos who has the middle lifestyle. He lives alone in a small house. He is looking for serious and real opportunities, basically, he has the opportunistic characteristics. Now he works as Repo Man in the dealership of American luxury cars.
Trevor is the psychotic character of GTA. He's a former colleague of Michael. He has a very high temper and outburst and rampages, which can be controlled. He doesn't like to live with other rules and live his life on his own. Also, he's a habitual drug abuser who lives in the countryside of the GTA map.