Citta del Vaticano vs urban center

Citta del Vaticano and urban center both are nouns.

Word	Noun	Adjective	Verb	Adverb
Citta del Vaticano	Yes	No	No	No
urban center	Yes	No	No	No

Citta del Vaticano (noun)	urban center (noun)
the capital of the State of the Vatican City	a large and densely populated urban area; may include several independent administrative districts