Distortion
From GuitarWiki
Guitar Distortion
Distortion is one of the most poular effects amongst guitarists today and is used in a large variety of genres ranging from pop to heavy metal, and on top of that it also comes in a variety of different forms, ranging from your mild overdrive sound favoured by George Harrison, to your fuzz like Hendrix.It is an effect that is built into most amplifiers today and can be purchased seperatly in a stomp box or multi effects unit, the reason you may want a pedal over your amp distortion is that each company's sound is different, and each company also has different ranges and styles of distortion. Guitar distortion is achieved when the electronic signal from the guitar is compressed and/or clipped. This results in added harmonics and sustain which give the original input signal a richer sound. There are several methods of achieving this result. The two most common methods are:
External links
Wikipedia.org has a more technical description of distortion.
