urban center vs Sarajevo

urban center and Sarajevo both are nouns.

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

urban center (noun)	Sarajevo (noun)
a large and densely populated urban area; may include several independent administrative districts	capital and largest city of Bosnia; scene of the assassination of Francis Ferdinand in 1914 which precipitated World War I