The variations are in a part of the guitar which might otherwise be considered as definite and absolute - the body. For an electric guitar the body itself may be hollow, as in the style of a classical or acoustic guitar. However, it could also be only partially hollow, and in many cases is entirely solid.

This is largely because of the fact that, unlike classical or acoustic guitars which rely on the hollow body of the guitar to reverberate and resonate the sound made from the string, an electric guitar relies on an electric amplifier to achieve this same resonance and sound, and the construction of the body is largely, though not entirely, irrelevant in terms of sound quality and resonance. Without the electronic amplifier and equipment connected to the electric guitar, the instrument makes very little sound on its own, and unlike an acoustic or classic guitar, cannot be played without electric amplification.

Fitted to the electric guitar are electromagnets which pick up the vibrations of the strings as movement, and this vibration or resonance is transmitted to the amplifier as an electrical signal. It is therefore the physical resonance or vibration of the string which is used to transfer a signal, and not the sound of the string being struck at all which generates the sound, or at least, not in a direct way.

In many cases the electrical signal from the electromagnetic pickup is transmitted through a cable directly to the amplifier, but in some cases this is done through radio waves, allowing the guitar to be played without any trailing cables - particularly useful for those who tend to move about a lot while playing their music. The fact that the guitar is being played without any direct cable connection to an amplifier or sound equipment should not be confused with an acoustic or classic guitar in any way - the amplifier is still necessary as the guitar on its own would make virtually no sound at all, and certainly nothing even remotely approaching that of an acoustic guitar.

Because of the fact that the signal from the electric guitar is fed electronically to the amplifier, it is often the case that other means are used to convert or modify the signal, providing extra tones, or effects that create unique voices for the guitar. Although often we tend to think of the guitar as being solely a part of rock music or pop music, in fact it has a very healthy heritage borne through the jazz and blues scene, and has managed to hold on to its status throughout these three main genres of jazz, blues and rock.

The commercialization of the electric guitar occurred in two places at pretty much the same time, with Gibson working alongside Les Paul, at the same time as the extremely well known Leo Fender was developing the commercial model of the Fender. The physical structure of the body of an electric guitar is what is most striking as it is very different from the design of an acoustic guitar. But the fret board is also quite different too, because of the height of the strings from the body of the guitar itself. In an acoustic guitar, the strings are very close to the body, so that they run very close to the edge of the hole in the center of the body, but in an electric guitar this proximity is not required for the simple reason that the body of the guitar is not used to amplify or resonate the sound produced at all.

Because the strings are further away from the body, this allows the musician to play an electric guitar in different ways from that of an acoustic or classic guitar, with techniques such as tapping or legato pull-offs being used extensively, and slurs - otherwise known as hammer-ons as well as pitch harmonics, swells of the volume and in many cases an arm which creates a tremolo effect. It is not unusual to see foot pedals being incorporated into the performance too.