Helen of Troy vs Greek mythology

Helen of Troy and Greek mythology both are nouns.

Word	Noun	Adjective	Verb	Adverb
Helen of Troy	Yes	No	No	No
Greek mythology	Yes	No	No	No

Helen of Troy (noun)	Greek mythology (noun)
(Greek mythology) the beautiful daughter of Zeus and Leda who was abducted by Paris; the Greek army sailed to Troy to get her back which resulted in the Trojan War	the mythology of the ancient Greeks