groundwork vs basis

groundwork and basis both are nouns.

Word	Noun	Adjective	Verb	Adverb
groundwork	Yes	No	No	No
basis	Yes	No	No	No

As nouns, groundwork and basis are synonyms defined as:

groundwork and basis: the fundamental assumptions from which something is begun or developed or calculated or explained

Other synonyms of groundwork include base, cornerstone, foundation, fundament.

groundwork (noun)	basis (noun)
preliminary preparation as a basis or foundation	the fundamental assumptions from which something is begun or developed or calculated or explained
lowest support of a structure	a relation that provides the foundation for something
the fundamental assumptions from which something is begun or developed or calculated or explained	the most important or necessary part of something