A cello bow is a specialized tool used to play the cello, a string instrument. It consists of a long, slender stick made from materials like wood or carbon fiber, with horsehair stretched between its ends. The horsehair is treated with rosin to create friction against the cello strings, producing sound when drawn across them. Cello bows come in various shapes and sizes, affecting their balance and playability. The two main types are the French bow, which has a curved shape and a frog that is mounted on the side, and the German bow, which is more straight and has a frog on the top. Each type offers different playing techniques and styles.