Electric Guitar Pickups are the mechanism that convert the puny acoustic signal from your electric axe into the electrical signal that can be amplified into rock overdrive.
These bad boys, more than any other component, define the sound of your instrument so understanding how they work is important to understand.
Depending on what brand of electric guitar you have, there is often 2 or 3 located at different spots on the guitar itself.
The musician can toggle between the different pickups by using a switch on the body and each combination produces a unique tone.
But all that aside - these fall into 2 main categories: Single and Dual Coil types.
Both types perform the exact same function, but the overall sound is slightly different and comes down to personal preference.
Like the name suggests, this style of electric guitar pickup uses a single coil of wires wrapped around a magnet.
As the steel strings move in relation to the magnet it creates an electrical signal.
They work in exactly the same way as the comparable magnetic (or sound hole pickups) that you'll see on an acoustic guitar.
By using only a single set of coils a certain amount of noise will be introduced to the guitar signal.
This can have a desirable effect when trying to go for a vintage overdrive tone (think Jimi Hendrix or Eddie Van Halen), but definitely add a gritty, edgy sound to your instrument.
These are the standard issue pickups for classic rock&roll guitars such as the immortal Fender Stratocaster.
They tend to have a grittier sound when compared to their Dual Coil counterparts.
Also referred to as Humbuckers, this style uses (and this should come as no surprise) two coils of wire to produce the electrical signal from the guitar strings.
So is that all there is to it??
Actually yeah... pretty much.
Think of the dual coil pickups as 2 single coil pickups placed side by side.
The advantage of this is that any noise from the signal (called Hum) will be canceled out due to the orientation of the 2 coils with respect to each other (and therefore the Hum is Bucked...get it).
The result is a very clean sound that can be cranked up quite high without noise creeping in (like our friends Paul McCartney and Slash).
This does not mean that you can't also overdrive these electric guitar pickups, but they are simply different in the way the initial sound is produced.
These can be found, for example, on Gibson Les Pauls and other guitars that strive for a warmer tone than their single coil screamer brethren.