urban center vs Cotonou

urban center and Cotonou both are nouns.

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

urban center (noun)	Cotonou (noun)
a large and densely populated urban area; may include several independent administrative districts	chief port of Benin on the Bight of Benin