The Immortals of the Ancient Greek pantheon can be divided into roughly eight classes.
The First of these were the Protogenoi or First Born Gods. These were the primeval beings who emerged at the start of creation to form the very fabric of the universe: Earth, Sea, Sky, Night, Day, etc. Although they were divinites, they were purely elemental in form: Gaia was the literal Earth, Pontus the Sea, and Ouranos the Dome of Heaven. However, they were sometimes represented assuming anthroporphic shapes, albeit ones that were indivisible from their native element. Gaia the earth, for example, might manifest herself as a matronly woman half-risen from the ground; and Thalassa the sea might lift her head above the waves in the shape of a sea-formed woman.
The Second were the nature Daimones (Spirits) and Nymphai (Nymphs) who nurtured life in the four elements. E.g. fresh-water Naiades, forest Dryades, beast-loving Satyroi, marine Tritones, etc.
The Third were the body- and mind-affecting DAIMONES (Spirits), the abstract personifications. E.g. Sleep (Hypnos), Love (Eros), Joy (Euphrosyne), Hate (Eris), Fear (Phobos), Death (Thanatos), Old Age (Geras), etc.
The Fourth class consisted of the Theoi (Gods) who controlled the forces of nature and bestowed civilised arts upon mankind.
- THEOI GEORGIKOI (Agricultural Earth Gods). E.g. Ploutos, etc.
THE FIFTH were the 12 Olympian Gods who governed the universe and commanded the legions of lesser gods and spirits. They were, namely,
- Zeus (Sky)
- Hera (Marraige)
- Poseidon (Sea)
- Demeter (Agriculture)
- Artemis (Moon, Hunting)
- Apollo (Sun, Music, Healing)
- Ares (Warfare)
- Athena (Strategy, Weaving)
- Aphrodite (Love)
- Hephaestus (Craftsmen)
- Hermes (Messengers, Commerce, Travel)
- Dionysus (Wine, Feestivities)
- Hestia (The Hearth)
The Sixth of the immortals were the spirits of the Constellations which circed the heavenly night sky. Every constellation, including the twelve signs of the Zodiac, was possessed of one or more spirits EG Saggitarius was the centaur Kheiron, Gemini the Dioskouroi Twins, etc.
The Seventh class consisted of the fabulous MONSTERS, BEASTS, GIANTS of myth. They were semi-divine creatures, closely related to the gods.E.g.GIGANTES (Giants), DRAKONES (Dragons), Kentauroi (Centaurs), Kerberos (Cerberus), Sphinx, Sirens, etc.
The Eight were the Heroi Hemitheoi (Semi-Divine Heroes) who were worshipped after death as minor divinities. They included great heroes like Achilles, Theseus and Perseus; heroines such as Alcmene, Helen and Baubo; and founding kings like Erikhthonios, Kadmos and Pelops.
There were many divinities in the Greek pantheon who fell into more than one of these categories. Tyche (Lady Fortune), for example, can easily be classified under category Two as an Okeanis Nymphe, Three as fortune personified, and Four as a popularly worshipped goddess.