atrocity vs brutality

atrocity and brutality both are nouns.

Word	Noun	Adjective	Verb	Adverb
atrocity	Yes	No	No	No
brutality	Yes	No	No	No

As nouns, brutality is a hyponym of atrocity; that is, brutality is a word with a more specific, narrower meaning than atrocity:

Other hyponyms of atrocity include barbarism, barbarity, savagery, outrage, enormity.

atrocity (noun)	brutality (noun)
an act of atrocious cruelty	a brutal barbarous savage act
the quality of being shockingly cruel and inhumane	the trait of extreme cruelty