urban center vs Seattle

urban center and Seattle both are nouns.

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

urban center (noun)	Seattle (noun)
a large and densely populated urban area; may include several independent administrative districts	a major port of entry and the largest city in Washington; located in west central Washington on the protected waters of Puget Sound with the snow-capped peaks of the Cascade Range and Mount Rainier visible to the south and east; an aerospace and computer center; site of the University of Washington