Oporto vs urban center

Oporto and urban center both are nouns.

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

Oporto (noun)	urban center (noun)
port city in northwest Portugal; noted for port wine	a large and densely populated urban area; may include several independent administrative districts