Rio vs urban center

Rio and urban center both are nouns.

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

Rio (noun)	urban center (noun)
the former capital and 2nd largest city of Brazil; chief Brazilian port; famous as a tourist attraction	a large and densely populated urban area; may include several independent administrative districts