A proper noun is a noun that refers to a specific person, place, or thing.

What is his real name?

Abstract nouns, unlike nouns that refer to concrete things, refer to concepts or states that do not have a specific shape or color.

He is learning how to use collective nouns.

'Apple' is a count noun, and you can count it as one, two, etc.

Nominalization is the linguistic process of converting verbs or adjectives into nouns.

Compound nouns are a very important part of Japanese grammar.

A noun phrase forms a major part of a sentence.

The one-eyed goblin was dancing in the forest.

Happiness is a mass noun, you can't count it.