urban center vs Smolensk

urban center and Smolensk both are nouns.

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

urban center (noun)	Smolensk (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in western Russia on the Dnieper River; scene of severe fighting in World War II