urban center vs Jiddah

urban center and Jiddah both are nouns.

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

urban center (noun)	Jiddah (noun)
a large and densely populated urban area; may include several independent administrative districts	port city in western Saudi Arabia on the Red Sea; near Mecca