foundation vs groundwork

foundation and groundwork both are nouns.

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

As nouns, foundation and groundwork are synonyms defined as:

Other synonyms of foundation include base, foot, fundament, substructure, understructure.

As nouns, foundation and groundwork are synonyms defined as:

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

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

foundation (noun)	groundwork (noun)
the act of starting something for the first time; introducing something new	preliminary preparation as a basis or foundation
lowest support of a structure	lowest support of a structure
a woman's undergarment worn to give shape to the contours of the body	the fundamental assumptions from which something is begun or developed or calculated or explained
the fundamental assumptions from which something is begun or developed or calculated or explained
education or instruction in the fundamentals of a field of knowledge
an institution supported by an endowment
the basis on which something is grounded