An electric guitar is a guitar that uses one or more pickups to convert the vibration of its strings into electrical signals. The vibration occurs when a guitar player strums, plucks, fingerpicks,slaps or taps the strings. The pickup used to sense the vibration generally uses electromagnetic induction to do so, though other technologies exist. In any case, the signal generated by an electric guitar is too weak to drive a loudspeaker, so it is fed to a guitar amplifier before being sent to the speaker(s), which converts it into audible sound.
Since the output of an electric guitar is an electric signal, it can be electronically altered to change the timbre of the sound. Often, the signal is modified using effects such as reverb, and distortion and "overdrive"; the latter effect is considered to be a key element of electric blues guitar music and rock guitar playing.