urban center vs Bonn

urban center and Bonn both are nouns.

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

urban center (noun)	Bonn (noun)
a large and densely populated urban area; may include several independent administrative districts	a city in western Germany on the Rhine River; was the capital of West Germany between 1949 and 1989