Chronology and Hierarchy
Firstly, the all powerful beings that brought the Titans into the world:
From the same Ancient Greek word meaning 'gaping void', 'abyss' or 'chasm'. The primordial force from which all life started, father to all subsequent deities.
2. Gaia aka Mother Gaia or Mother Nature
Comes from the Ancient Greek word for 'land' or 'earth'.
3. Ouranos aka Uranus or Father Sky
Comes from the Ancient Greek word for 'sky'. Consort and son to Gaia.
Primordial goddess of the night, sister to Erebus. She gave birth to the following gods: Apate, Eris, Keres, Philotes, and Moros.
Meaning 'shadow' or 'darkness', consort and brother to Nyx. They sired the following lesser gods together: Charon, Aether, Hemera, Momus, Geras, Oneiroi, Moirai, Nemesis, Hesperides, Hypnos, and Thanatos.
Gaia and Ouranos bore 12 children together, the Titans as we know them (listed as oldest first, youngest last):
7. Rhea - Ruled over Olympus with Cronus after overthrowing Gaia and Ouranos. Mother to the god Zeus
11. Tethys - Sea goddess, was both sister and wife to Oceanus.
12. Cronus - The most ambitious of all Titans, and was the one who led the fight against his parents. Father to the god Zeus