metropolis vs Joao Pessoa

metropolis and Joao Pessoa both are nouns.

Word	Noun	Adjective	Verb	Adverb
metropolis	Yes	No	No	No
Joao Pessoa	Yes	No	No	No

metropolis (noun)	Joao Pessoa (noun)
people living in a large densely populated municipality	a city in northeastern Brazil near the Atlantic Ocean to the north of Recife
a large and densely populated urban area; may include several independent administrative districts