Each other is a reciprocal pronoun by which we show two or more people are involved in an action, and these people give or do the same thing to each other, and both sides are involved in a relationship. For example: Kylie and Steve hate each other.

Each other like all pronouns refers back to a noun that comes before it (an antecedent). However, because it is a reciprocal pronoun, it refers to two nouns or a group noun. It expresses what one person feels toward or does for the other; the other feels or does the same in return.