city vs Santos

city and Santos both are nouns.

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

city (noun)	Santos (noun)
people living in a large densely populated municipality	a port city in southwestern Brazil on an offshore island near Sao Paulo
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter