urban center vs municipality

urban center and municipality both are nouns.

Word	Noun	Adjective	Verb	Adverb
urban center	Yes	No	No	No
municipality	Yes	No	No	No

As nouns, municipality is a hypernym of urban center; that is, municipality is a word with a broader meaning than urban center:

urban center: a large and densely populated urban area; may include several independent administrative districts
municipality: an urban district having corporate status and powers of self-government

urban center (noun)	municipality (noun)
a large and densely populated urban area; may include several independent administrative districts	people living in a town or city having local self-government
	an urban district having corporate status and powers of self-government