Dave, can you find like a video or something on it? I cant really find anything.
I'm sure there are tutorials around on the net, but I've never looked for anything as this is stuff I learned 45 years ago.
I'll do my best to provide some insight.
Please forgive my crappy drawings, I don't have a drawing editor on this system, so I used a little DOS one I wrote about 30 years ago to send simple drawings over Fidonet.
A pot is normally used as a variable voltage divider.
Consider the attached drawing RESIST.JPG this shows a simple resistive voltage divider: VOUT is VIN x R2 / (R1+R2)
A pot basically allows you to change the R1 and R2 values. For example, a 10K pot will always have (R1+R2) = 10k, but R1 and R2 can be any combination that adds up to 10k,
So.. for VIN = 10volts
if R1 = 10k and R2 = 0k, then VOUT = 10 x 0 / 10 = 0 Volts.
If R1 = 9k and R2 = 1k, then VOUT = 10 x 1 / 10 or 1 volt.
if R1 = 5k and R2 = 5k, then VOUT = 10 x 5 / 10 or 5 volts.
If R1 = 1K and R2 = 9k, then VOUT = 10 x 9 / 10 or 9 volts.
If R1 = 0k and R2 = 10k, then VOUT = 10 x 10 / 10 or 10 volts.
Thus you can take the signal into an amplifier and divide it down to any lower value you like, thereby effectively controlling the gain of the amplifier.
The majority of pots are rotary, although there are other types (eg: linear such is used on equalizers, DJ mixers etc.)
I've tried to give an idea of how a rotary pot is constructed in POT.JPG
The resistive material is arranged in an arc, with a terminal at each end, and a wiper attached to the center tap terminal. As the control knob is turned, the wiper moves around the arc, adjusting the point at which is contacts the resistive material. In the above discussion R1 would be the resistance of the material between the wiper and one end terminal, R2 would be the resistance of the material between the wiper and the other end terminal.
POTS.JPG contains a photo of some actual pots from my junkbox.
On the left is a pot with the back off. You can see the resistive material and the wiper. Although you can't see the shaft, it comes out directly from the center (look at the others).
This happens to be a "wire wound" pot, which means the resistive material happens to be a coil of fine nichrome "resistance" wire wrapped around the arc shaped form, but that doesn't matter for this discussion (I chose it because it is easy to see the arc and wiper).
The center pot is a typical panel mount single pot, you should be able to imagine how it works having seen the left one.
The pot on the right is a dual ganged pot. As you can see it is simply two single pots attached together. The shaft passes through the first pot and enters the second exactly as it would in a single pot. The two sets of three terminals are electrically independent. As far as any circuits are concerned, this is two separate pots - the only connection is the mechanical one caused by sharing the same shaft.
Hopefully this will all make sense...
Dave