Salzburg vs urban center

Salzburg and urban center both are nouns.

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

Salzburg (noun)	urban center (noun)
city in western Austria; a music center and birthplace of Mozart	a large and densely populated urban area; may include several independent administrative districts