Saratov vs urban center

Saratov and urban center both are nouns.

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

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