Why is Twelfth Night called a comedy?

Twelfth Night or What You Will is a comedy by William Shakespeare, believed to have been written around 1601–02 as a Twelfth Night's entertainment for the close of the Christmas season.[1] The play revolves around the twins Viola and Sebastian, who are separated in a shipwreck. Viola disguises herself as a man and becomes a page in the court of the Duke of Illyria, where she falls in love with the Duke but disguises her feelings.[2] Meanwhile, the Count Orsino, whom Olivia loves in vain, is convinced by Viola, disguised as a man named Cesario, to pursue Olivia. The play contains many instances of mistaken identity and confusion, as well as satirical elements in the characters of Sir Andrew Aguecheek, Sir Toby Belch, Maria and Feste the Clown.