Desdemona, Iago, and Cassio are all characters in William Shakespeare's play "Othello". Desdemona is the wife of the title character, Othello, while Iago is his cunning and manipulative ensign. Cassio is a young and promising soldier who is promoted as Othello's lieutenant, which sets off a chain of events that lead to tragic consequences. "Othello" is a tragedy that explores themes of jealousy, betrayal, racism, and love, and is considered one of Shakespeare's most powerful and moving plays.