nonidentity vs otherness

nonidentity and otherness both are nouns.

Word	Noun	Adjective	Verb	Adverb
nonidentity	Yes	No	No	No
otherness	Yes	No	No	No

As nouns, otherness is a hypernym of nonidentity; that is, otherness is a word with a broader meaning than nonidentity:

nonidentity: Difference, distinction; failure to be identical.
otherness: the quality of being not alike; being distinct or different from that otherwise experienced or known

Other hypernyms of nonidentity include distinctness, separateness.

nonidentity (noun)	otherness (noun)
Difference, distinction; failure to be identical.	the quality of being not alike; being distinct or different from that otherwise experienced or known