NounsA noun is a word for a person,

Nouns
A noun is a word for a person, place, or thing. (You might like to think of nouns as naming words.)

Everything we can see or talk about is represented by a word which names it. That "naming word" is called a noun.

Sometimes a noun will be the name for something we can touch (e.g., lion, cake, computer), and sometimes a noun will be the name for something we cannot touch (e.g., bravery, mile, joy).

Everything is represented by a word that lets us talk about it. This includes people (e.g., man, scientist), animals (e.g., dog, lizard), places (e.g., town, street), objects (e.g., vase, pencil), substances (e.g., copper, glass), qualities (e.g., heroism, sorrow), actions (e.g., swimming, dancing), and measures (e.g., inch, ounce).
Read more at http://www.grammar-monster.com/lessons/nouns.htm#W5dRgao2s8cqbxxv.99