urban center vs Babylon

urban center and Babylon both are nouns.

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

urban center (noun)	Babylon (noun)
a large and densely populated urban area; may include several independent administrative districts	the chief city of ancient Mesopotamia and capital of the ancient kingdom of Babylonia