Nanjing vs urban center

Nanjing and urban center both are nouns.

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

Nanjing (noun)	urban center (noun)
a city in eastern China on the Yangtze River; a former capital of China; the scene of a Japanese massacre in the 1930s	a large and densely populated urban area; may include several independent administrative districts