urban center vs Mosul

urban center and Mosul both are nouns.

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

urban center (noun)	Mosul (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in northern Iraq on the Tigris across from the ruins of Nineveh