credit union vs banking company

credit union and banking company both are nouns.

Word	Noun	Adjective	Verb	Adverb
credit union	Yes	No	No	No
banking company	Yes	No	No	No

As nouns, banking company is a hypernym of credit union; that is, banking company is a word with a broader meaning than credit union:

credit union: a cooperative depository financial institution whose members can obtain loans from their combined savings
banking company: a financial institution that accepts deposits and channels the money into lending activities

Other hypernyms of credit union include bank, banking concern, depository financial institution.

credit union (noun)	banking company (noun)
a cooperative depository financial institution whose members can obtain loans from their combined savings	a financial institution that accepts deposits and channels the money into lending activities