What is the purpose of pucks final speech?

Puck speaks these lines in an address to the audience near the end of A Midsummer Night's Dream, extending the theme of dreams beyond the world of the play and putting the reality of the audience's experience into question (V.epilogue.1-8). As many of the characters (Bottom and Theseus among them) believe that the magical events of the play's action were merely a dream, Puck tells the crowd that if the play has offended them, they too should remember it simply as a dream-"That you have but slumbered here, / While these visions did appear." The speech offers a commentary on the dreamlike atmosphere of A Midsummer Night's Dream and casts the play as a magical dream in which the audience shares.