revision vs written material

revision and written material both are nouns.

Word	Noun	Adjective	Verb	Adverb
revision	Yes	No	No	No
written material	Yes	No	No	No

As nouns, written material is a hypernym of revision; that is, written material is a word with a broader meaning than revision:

revision: something that has been written again
written material: the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)

Other hypernyms of revision include piece of writing, writing.

revision (noun)	written material (noun)
the act of revising or altering (involving reconsideration and modification)	the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)
something that has been written again
the act of rewriting something