elaboration vs expansion

elaboration and expansion both are nouns.

Word	Noun	Adjective	Verb	Adverb
elaboration	Yes	No	No	No
expansion	Yes	No	No	No

As nouns, expansion is a hypernym of elaboration; that is, expansion is a word with a broader meaning than elaboration:

elaboration: addition of extra material or illustration or clarifying detail
expansion: adding information or detail

Other hypernyms of elaboration include expanding upon.

As nouns, elaboration and expansion are synonyms defined as:

elaboration and expansion: a discussion that provides additional information

Other synonyms of elaboration include enlargement.

elaboration (noun)	expansion (noun)
developing in intricate and painstaking detail	the act of increasing (something) in size or volume or quantity or scope
addition of extra material or illustration or clarifying detail	adding information or detail
marked by elaborately complex detail	a discussion that provides additional information
a discussion that provides additional information	a function expressed as a sum or product of terms
the result of improving something