urban center vs Sfax

urban center and Sfax both are nouns.

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

urban center (noun)	Sfax (noun)
a large and densely populated urban area; may include several independent administrative districts	the second largest city in Tunisia; located in eastern Tunisia near a phosphate region