sexism vs discrimination

sexism and discrimination both are nouns.

Word	Noun	Adjective	Verb	Adverb
sexism	Yes	No	No	No
discrimination	Yes	No	No	No

As nouns, discrimination is a hypernym of sexism; that is, discrimination is a word with a broader meaning than sexism:

sexism: discriminatory or abusive behavior towards members of the opposite sex
discrimination: unfair treatment of a person or group on the basis of prejudice

Other hypernyms of sexism include favoritism, favouritism.

sexism (noun)	discrimination (noun)
discriminatory or abusive behavior towards members of the opposite sex	unfair treatment of a person or group on the basis of prejudice
	the cognitive process whereby two or more stimuli are distinguished