In Greek mythology there were many powerful gods. Some were the Titans and some were the Olympians. Others were the lessor gods.
The Titans were elder gods. They ruled the Earth before the Olympians overthrew them. Most of the Titans fought against Cronus's son, Zeus, and were punished by being banished to Tartarus. There were 18 Titans all together.
Cronus was the ruling titan. Gaea, another Titan, was the Earth goddess. Uranus, the sky god was the first ruler until Cronus took over. Oceanus was the water that is circling the world. He is the father of the sun, moon, and dawn. All of these Titans have something to do with the solar system or Earth. Prometheus is the wisest of all Titans for he could foretell the future. Prometheus is the protector and benefactor of man.
He gave man many things including fire. Atlas, another powerful Titan, lead the Titans into battle against Zeus. Since he did this he carries the world on his back and is to never let it fall. Metis is the planet of Mercury. She is a very wise goddess.