Just help me visualize the electron flow.

The common analogy is **the old water pipe analogy -**

Voltage (sometimes called "potential") is similar to water pressure. The voltage is always there (under "normal conditions") whether current (water) is flowing or not. You can measure voltage with a multimeter (or with the Arduino) and almost no current flows.

With higher voltage (water pressure) more current (water) flows.

A skinny pipe or a water valve turned part way on "resists" and reduces water flow similarly to how resistance or impedance resists or reduces electrical current flow.

The analogy is NOT perfect... The biggest difference is that if you cut a pipe, resistance goes to zero and lots of water flows out all over the place. If you cut a wire, resistance goes to infinity and no current flows.

Also, zero water resistance doesn't damage anything (unless there is a flood ) whereas zero electrical resistance (a short) can fry your electronics.

When John is explaining how a pot works, he's describing a variable **[u]Voltage Divider[/u]**.

**[u]Ohm's Law[/u]** describes the relationship between voltage, current, and resistance, and if you understand Ohm's Law, you an apply it to a voltage divider to understand how a voltage divider works if you also know that the current through (two or more) series resistors is the same in both resistors (just as the water current through two series pipes would be the same).

Just help me visualize the electron flow.

You don't need to worry about this right now but I'm going to mention one picky detail... **In the field of electronics we use "conventional current flow" where the current flows from positive-to-negative**, which is logical... high-to-low. **But, The electrons actually flow the opposite direction.** The early scientists got the + & - terminals on a battery labeled wrong (before they knew about electrons), and in the field of electricity/electronics it was never changed...

If you take an electronics class, you'll learn that current flows positive-to-negative. If you take a physics or chemistry class, you'll learn that electrons flow negative-to-positive.