Novosibirsk vs urban center

Novosibirsk and urban center both are nouns.

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

Novosibirsk (noun)	urban center (noun)
a city in the Asian part of Russia on the Ob river; largest city in Siberia	a large and densely populated urban area; may include several independent administrative districts