nepotism vs favouritism

nepotism and favouritism both are nouns.

Word	Noun	Adjective	Verb	Adverb
nepotism	Yes	No	No	No
favouritism	Yes	No	No	No

As nouns, favouritism is a hypernym of nepotism; that is, favouritism is a word with a broader meaning than nepotism:

nepotism: favoritism shown to relatives or close friends by those in power (as by giving them jobs)
favouritism: unfair treatment of a person or group on the basis of prejudice

Other hypernyms of nepotism include discrimination, favoritism.

nepotism (noun)	favouritism (noun)
favoritism shown to relatives or close friends by those in power (as by giving them jobs)	unfair treatment of a person or group on the basis of prejudice
	an inclination to favor some person or group