urban center vs Luoyang

urban center and Luoyang both are nouns.

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

urban center (noun)	Luoyang (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in east central China; the capital of ancient China during several dynasties