A reflexive pronoun is a type of pronoun that refers back to the subject of the sentence, typically indicating that the subject performs an action on itself. These pronouns are essential for clarifying relationships between subjects and actions, often enhancing the meaning of sentences by providing context about who is affected by the action. Common reflexive pronouns include 'myself,' 'yourself,' 'himself,' 'herself,' 'itself,' 'ourselves,' 'yourselves,' and 'themselves.'