noun vs mass noun

noun and mass noun both are nouns.

Word	Noun	Adjective	Verb	Adverb
noun	Yes	No	No	No
mass noun	Yes	No	No	No

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

noun: a content word that can be used to refer to a person, place, thing, quality, or action
mass noun: a noun that does not form plurals

noun (noun)	mass noun (noun)
a content word that can be used to refer to a person, place, thing, quality, or action	a noun that does not form plurals
the word class that can serve as the subject or object of a verb, the object of a preposition, or in apposition