Krakau vs urban center

Krakau and urban center both are nouns.

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

Krakau (noun)	urban center (noun)
an industrial city in southern Poland on the Vistula	a large and densely populated urban area; may include several independent administrative districts