Busan vs urban center

Busan and urban center both are nouns.

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

Busan (noun)	urban center (noun)
a city in southeastern South Korea on the Korean Strait; the chief port and second largest city	a large and densely populated urban area; may include several independent administrative districts