validation vs substantiation

validation and substantiation both are nouns.

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

As nouns, validation and substantiation are synonyms defined as:

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

Other synonyms of validation include proof.

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