Pronouns are a type of word used instead of a noun noun phrase. They are noun or noun phrase substitutes.

Pronoun
In English language pronouns can be Personal Pronouns, Reflexive Pronouns , Possessive Pronouns, Interrogative Pronouns, Relative Pronouns, Demonstrative Pronouns, Indefinite Pronouns, Intensive pronouns, Reciprocal Pronouns, Distributive Pronouns.