They lived in a cloud palace on Mount Olympus, ruling over the ancient Greeks. Those that lived on the mountain came to power when their leader Zeus killed his father. They were all related, living fairly normal lives but theirs was life eternal. The heroes in Greek mythology were usually descended from human and godly interaction.
Only the top twelve gods lived on the mountain but there were literally hundreds of other gods that make appearances in Greek mythology. The Greeks built them temples and bestowed upon them human emotions that ranged from petty to spiteful, and benevolent to insane.
The civilians attributed actions to the gods in an attempt to explain the inexplicable. Sometimes the gods ignored them. At other times they sent storms and pestilence. The gods were also the deciders of victory in battle.
When Rome conquered Greece at the Battle of Corinth in 146BC, they took on all the Greek deities, giving them Roman names. The gods of Greece have inspired paintings and sculptures across the ages well after people stopped believing in them. The adventures of these gods have been the subject of many epic movies over time. They have left an indelible mark on our culture.