Ciudad Bolivar vs urban center

Ciudad Bolivar and urban center both are nouns.

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

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