root word vs word form

root word and word form both are nouns.

Word	Noun	Adjective	Verb	Adverb
root word	Yes	No	No	No
word form	Yes	No	No	No

As nouns, word form is a hypernym of root word; that is, word form is a word with a broader meaning than root word:

root word: (linguistics) the form of a word after all affixes are removed
word form: the phonological or orthographic sound or appearance of a word that can be used to describe or identify something

Other hypernyms of root word include descriptor, form, signifier.

root word (noun)	word form (noun)
(linguistics) the form of a word after all affixes are removed	the phonological or orthographic sound or appearance of a word that can be used to describe or identify something