identity vs sameness

identity and sameness both are nouns.

Word	Noun	Adjective	Verb	Adverb
identity	Yes	No	No	No
sameness	Yes	No	No	No

As nouns, sameness is a hypernym of identity; that is, sameness is a word with a broader meaning than identity:

identity (noun)	sameness (noun)
the distinct personality of an individual regarded as a persisting entity	the quality of being alike
exact sameness	the quality of wearisome constancy, routine, and lack of variety
the individual characteristics by which a thing or person is recognized or known
an operator that leaves unchanged the element on which it operates