What does the tone knob on an electric guitar do?

[Triode]

I know you can find this on google, but its never in electronic terms, it's usually more like "it makes the tone fuller or thinner". Can someone explain it to me, or point me to an article that explains it, in terms of what it adjusts and connects to in terms of electronics?

 

[gabeNC]

Here's a few schematics.

**broken link removed**

To simplify it, when turning the knob you are bleeding treble to ground.

this was an interesting article for capacitor value.

**broken link removed**