urban center vs Calgary

urban center and Calgary both are nouns.

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

urban center (noun)	Calgary (noun)
a large and densely populated urban area; may include several independent administrative districts	the largest city in southern Alberta; an oil and gas center and a technology center for Alberta and most of western Canada