sentiment vs belief

sentiment and belief both are nouns.

Word	Noun	Adjective	Verb	Adverb
sentiment	Yes	No	No	No
belief	Yes	No	No	No

As nouns, belief is a hypernym of sentiment; that is, belief is a word with a broader meaning than sentiment:

sentiment: a personal belief or judgment that is not founded on proof or certainty
belief: any cognitive content held as true

sentiment (noun)	belief (noun)
a personal belief or judgment that is not founded on proof or certainty	any cognitive content held as true
tender, romantic, or nostalgic feeling or emotion	a vague idea in which some confidence is placed