noun vs concrete noun

noun and concrete noun both are nouns.

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

As nouns, concrete noun is a hyponym of noun; that is, concrete 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
concrete noun: the name of an object which may be perceived by one or more of the five senses.

noun (noun)	concrete noun (noun)
a content word that can be used to refer to a person, place, thing, quality, or action	the name of an object which may be perceived by one or more of the five senses.
the word class that can serve as the subject or object of a verb, the object of a preposition, or in apposition