urban center vs Sioux Falls

urban center and Sioux Falls both are nouns.

Word	Noun	Adjective	Verb	Adverb
urban center	Yes	No	No	No
Sioux Falls	Yes	No	No	No

urban center (noun)	Sioux Falls (noun)
a large and densely populated urban area; may include several independent administrative districts	largest city in South Dakota; located in southeastern South Dakota