The Tempest is most commonly known as a comedy. It appeared in the First Folio in 1623 in this category. According to convention, comedies resolve happily, usually with a wedding. To that end, The Tempest concludes with the promise of marriage between Miranda and Ferdinand. In Act 4, Scene 1, Prospero orders his band of spirits to put on a celebratory performance for the young couple. Iris, Juno, and Ceres sing songs to bless their marriage, and the joyful scene confirms the resolution of many conflicts—the young lovers unite, and Prospero is inspired to forgive Antonio (Ferdinand's father).
However, it is important to keep in mind how much conflict and confusion occur before this point in the play. Indeed, The Tempest includes two attempted assassinations, attempted rape, brotherly backstabbing, and slavery. It opens with the scene of a raging tempest, the revelation of betrayal, and the possibility of revenge. All of these elements create an initial sense of doubt that the play will have a positive conclusion. But Shakespeare, like Prospero, works his magic, and the tragic beginning morphs into a happy ending. No one dies, misunderstandings are resolved, and the young lovers promise to unite in marriage.