Who were the Gods and Goddesses who were considered the Chthonic Gods What did explanation did they provide for Greek Society?

Answer 1

Chthonic (from Greek χθόνιος - chthonios, "in, under, or beneath the earth", from χθών - chthōn"earth"; pertaining to the Earth; earthy; subterranean) designates, or pertains to, deities or spirits of the underworld, especially in relation to Greek religion.

Greek khthon is one of several words for "earth"; it typically refers to the interior of the soil, rather than the living surface of the land (as Gaia or Ge does) or the land as territory (as khora (χώρα) does). It evokes at once abundance and the grave.

While terms such as "Earth deity" have rather sweeping implications in English, the words khthonie and khthonios had a more precise and technical meaning in Greek, referring primarily to the manner of offering sacrifices to the deity in question.

Some chthonic cults practised ritual sacrifice, which often happened at night time. When the sacrifice was a living creature, the animal was placed in a bothros ("pit") or megaron("sunken chamber"). In some Greek chthonic cults, the animal was sacrificed on a raised bomos ("altar"). Offerings usually were burned whole or buried rather than being cooked and shared among the worshippers.

Not all Chthonic cults were Greek, nor did all cults practice ritual sacrifice; some performed sacrifices in effigy or burnt vegetable offerings.