urban center vs Ciudad Bolivar

urban center and Ciudad Bolivar both are nouns.

Word	Noun	Adjective	Verb	Adverb
urban center	Yes	No	No	No
Ciudad Bolivar	Yes	No	No	No

urban center (noun)	Ciudad Bolivar (noun)
a large and densely populated urban area; may include several independent administrative districts	a port in eastern Venezuela on the Orinoco river