city vs Hannover

city and Hannover both are nouns.

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

city (noun)	Hannover (noun)
people living in a large densely populated municipality	a port city in northwestern Germany; formerly a member of the Hanseatic League
a large and densely populated urban area; may include several independent administrative districts
an incorporated administrative district established by state charter