Sfax vs urban center

Sfax and urban center both are nouns.

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

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