substantiation vs validation

substantiation and validation both are nouns.

Word	Noun	Adjective	Verb	Adverb
substantiation	Yes	No	No	No
validation	Yes	No	No	No

As nouns, substantiation and validation are synonyms defined as:

substantiation and validation: the act of validating; finding or testing the truth of something

Other synonyms of substantiation include proof.

substantiation (noun)	validation (noun)
the act of validating; finding or testing the truth of something	the act of validating; finding or testing the truth of something
additional proof that something that was believed (some fact or hypothesis or theory) is correct	the cognitive process of establishing a valid proof