How is a concrete noun different from an abstract noun?
Concrete nouns refer to people, places, or things that are physically observable to the senses. Examples include “Mrs. Robins,” “snowstorm,” “San Juan,” “moonlight,” and “book.”
Abstract nouns, in contrast, name constructs that can’t be observed with the senses, such as ideas, moods, and values. Examples include “nostalgia,” “weekday,” “peace,” “era,” and “academia.”