foundation vs basis

foundation and basis both are nouns.

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

As nouns, foundation and basis are synonyms defined as:

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

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

As nouns, basis is a hyponym of foundation; that is, basis is a word with a more specific, narrower meaning than foundation:

Other hyponyms of foundation include footing, ground, grass roots.

foundation (noun)	basis (noun)
the act of starting something for the first time; introducing something new	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
a woman's undergarment worn to give shape to the contours of the body	the most important or necessary part of something
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