rest on vs build upon

rest on and build upon both are verbs.

Word	Noun	Adjective	Verb	Adverb
rest on	No	No	Yes	No
build upon	No	No	Yes	No

As verbs, rest on and build upon are synonyms defined as:

Other synonyms of rest on include build on, repose on.

rest on (verb)	build upon (verb)
rest on for support	use as a basis for theories and claims
use as a basis for theories and claims