jeans vs Levi's

jeans and Levi's both are nouns.

Word	Noun	Adjective	Verb	Adverb
jeans	Yes	No	No	No
Levi's	Yes	No	No	No

As nouns, Levi's is a hyponym of jeans; that is, Levi's is a word with a more specific, narrower meaning than jeans:

jeans: (used in the plural) close-fitting trousers of heavy denim for manual work or casual wear
Levi's: a popular brand of jeans

Other hyponyms of jeans include levis, distressed jeans.

jeans (noun)	Levi's (noun)
(used in the plural) close-fitting trousers of heavy denim for manual work or casual wear	a popular brand of jeans