urban center vs Mombasa

urban center and Mombasa both are nouns.

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

urban center (noun)	Mombasa (noun)
a large and densely populated urban area; may include several independent administrative districts	a port city in southern Kenya on a coral island in a bay of the Indian Ocean