Busan vs city

Busan and city both are nouns.

Word	Noun	Adjective	Verb	Adverb
Busan	Yes	No	No	No
city	Yes	No	No	No

Busan (noun)	city (noun)
a city in southeastern South Korea on the Korean Strait; the chief port and second largest city	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts
	an incorporated administrative district established by state charter