A noun is a word used as a name of a person place or thing.

Kinds:-

1. Common - A name given in common to every person or thing of a same class or kind.
2. Proper - A name of a particular person or place.
3. Collective - A name of a number or collection or persons or things.
4. Abstract - A name of a quality action or state considered apart from the object it belongs to.

e.g.:-
1. Akbar was a great king.
(Here, Akbar is a proper noun and king is a common noun.)
2. The flock of flamingos was a sight of great beauty.
(Here, flock is a common noun and beauty is an abstract noun.)