In Greek mythology, how was Prometheus related to Zeus?

Prometheus is the one that gave the mortals fire. That was a big no-no!! When Zues found out, he impaled Promethues to a mountain and exposed his liver. Everyday the birds ate it and everyday it grew back and the birds ate it over and over again. Hercules freed him not knowing Zues put him there. Zues let him live after that. I study Greek Mythology and I hope I have my facts straight. I hope I do!!!