Kirkuk vs urban center

Kirkuk and urban center both are nouns.

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

Kirkuk (noun)	urban center (noun)
a city in northeastern Iraq; the center of a rich oilfield with pipelines to the Mediterranean	a large and densely populated urban area; may include several independent administrative districts