urban center vs Rawalpindi

urban center and Rawalpindi both are nouns.

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

urban center (noun)	Rawalpindi (noun)
a large and densely populated urban area; may include several independent administrative districts	an ancient city in northeastern Pakistan; served as capital of Pakistan while Islamabad was being built