urban center vs Rostock

urban center and Rostock both are nouns.

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

urban center (noun)	Rostock (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in northeastern Germany near the Baltic sea; an important member of the Hanseatic League in the 14th century