urban center vs Hamburg

urban center and Hamburg both are nouns.

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

urban center (noun)	Hamburg (noun)
a large and densely populated urban area; may include several independent administrative districts	a port city in northern Germany on the Elbe River that was founded by Charlemagne in the 9th century and is today the largest port in Germany; in 1241 it formed an alliance with Lubeck that became the basis for the Hanseatic League