noun vs content word

noun and content word both are nouns.

Word	Noun	Adjective	Verb	Adverb
noun	Yes	No	No	No
content word	Yes	No	No	No

As nouns, content word is a hypernym of noun; that is, content word is a word with a broader meaning than noun:

noun: a content word that can be used to refer to a person, place, thing, quality, or action
content word: a word to which an independent meaning can be assigned

Other hypernyms of noun include open-class word, substantive.

noun (noun)	content word (noun)
a content word that can be used to refer to a person, place, thing, quality, or action	a word to which an independent meaning can be assigned
the word class that can serve as the subject or object of a verb, the object of a preposition, or in apposition