A concrete noun is a word for something that can be experienced by any of the five senses; it can be seen, heard, smelled, tasted, or touched. A concrete noun is something physical.
Example concrete nouns: apple, building, child, Denmark, eagle, finger, grass, horse, ice, Jello, knees, lunchbox, mountain, etc.
A abstract noun is a word for something that can not be experienced by any of the five senses; it is something that we know, learn, understand, imagine, or feel emotionally.
Example abstract nouns: anger, belief, curiosity, danger, environment, fun, gratitude, help, independence, joy, knowledge, love, month, etc.