A Noun is a word (other than a pronoun) used to identify any of a class of people, places, things, substance, or quality.: book, wish, idea, beauty, etc.
A1. Nouns are one of the four major word classes, along with verbs, adjectives and adverbs. Noun types are: Proper noun, Concrete noun and Abstract noun.
a. Proper nouns are the names of specific people, animals and things. The Proper Noun is written with a capital letter at the start.
b. Concrete nouns refer to material objects which we can see or touch.
c. Abstract nouns refer to things which are not material objects, such as ideas, feelings and situations.
A2. A Noun can be Countable (C) or Uncountable (U).
A3. A Countable Noun can be a Singular and Plural countable noun.