metropolis vs Salzburg

metropolis and Salzburg both are nouns.

Word	Noun	Adjective	Verb	Adverb
metropolis	Yes	No	No	No
Salzburg	Yes	No	No	No

metropolis (noun)	Salzburg (noun)
people living in a large densely populated municipality	city in western Austria; a music center and birthplace of Mozart
a large and densely populated urban area; may include several independent administrative districts