Gaea vs Gaia

Gaea and Gaia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Gaea	Yes	No	No	No
Gaia	Yes	No	No	No

As nouns, Gaea and Gaia are synonyms defined as:

Gaea and Gaia: (Greek mythology) goddess of the earth and mother of Cronus and the Titans in ancient mythology

Other synonyms of Gaea include Ge.

Gaea (noun)	Gaia (noun)
(Greek mythology) goddess of the earth and mother of Cronus and the Titans in ancient mythology	(Greek mythology) goddess of the earth and mother of Cronus and the Titans in ancient mythology