An electric guitar is a guitar that uses a pickup to convert the vibration of its strings into electrical impulses. The most common guitar pickup uses the principle of direct electromagnetic induction. The signal generated by an electric guitar is too weak to drive a loudspeaker, so it is amplified before sending it to a loudspeaker. Since the output of an electric guitar is an electric signal, the signal may easily be altered using electronic circuits to add "color" to the sound. Often the signal is modified using effects such as reverb and distortion.
Electric guitar design and construction varies greatly as to the shape of the body, and configuration of the neck, bridge, and pickups. Guitars have a fixed bridge or a spring-loaded hinged bridge that lets players bend notes or chords up or down in pitch, or perform a vibrato.