A couplet is a pair of lines in poetry that usually rhyme and have the same meter. This structure often conveys a complete thought or idea, making it a popular choice for poets. Couplet forms can be found in various types of poetry, including sonnets and narrative poems. Couplets can enhance the musical quality of a poem and create a sense of closure. Famous poets like William Shakespeare and Alexander Pope frequently used couplets in their works, showcasing their ability to express complex emotions and themes in just two lines.