Binary form is a musical structure that consists of two contrasting sections, typically labeled as A and B. Each section is usually repeated, creating a simple yet effective framework for composition. This form is commonly found in various genres, including classical and folk music, allowing composers to explore different themes and ideas. In binary form, the A section often introduces a melody or theme, while the B section provides contrast, either through a different melody or a change in key. This structure helps to create a sense of balance and variety, making it a popular choice for many composers throughout music history.