urban center vs Saratov

urban center and Saratov both are nouns.

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

urban center (noun)	Saratov (noun)
a large and densely populated urban area; may include several independent administrative districts	an industrial city in the European part of Russia, and the administrative center of Saratov Oblast, Russia