ism vs belief

ism and belief both are nouns.

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

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

ism: a belief (or system of beliefs) accepted as authoritative by some group or school
belief: any cognitive content held as true

ism (noun)	belief (noun)
a belief (or system of beliefs) accepted as authoritative by some group or school	any cognitive content held as true
	a vague idea in which some confidence is placed