Final answer:
A comedy is a light, humorous play that typically ends on a happy note, often with a wedding, and is designed to entertain and amuse the audience.
Step-by-step explanation:
A light, humorous play that ends happily is defined as a comedy. Comedies often revolve around entertaining situations and characters who may be commonplace or even bawdy. These plays traditionally culminate in a joyous event, such as a marriage, exemplified in works like William Shakespeare's A Midsummer Night's Dream. In terms of structure, whether discussing a tragedy, comedy, history, or romance, plays generally follow the format of act, scene, and line. Unlike drama, which delves more into the psychological journey of characters and does not always conclude with happiness, comedies focus on amusing practical dilemmas and aim to induce laughter and enjoyment with a satisfying ending.