String instruments are musical instruments that produce sound from vibrating strings when the performer plays or sounds the strings in some manner. Musicians play some string instruments by plucking the strings with their fingers or a plectrum — and others by hitting the strings with a light wooden hammer or by rubbing the strings with a bow. In most string instruments, the vibrations are transmitted to the body of the instrument, which often incorporates some sort of hollow or enclosed area. The body of the instrument also vibrates, along with the air inside it. The vibration of the body of the instrument and the enclosed hollow or chamber make the vibration of the string more audible to the performer and audience.