What is a Potentiometer?

A Potentiometer is a variable resistor that has 3 terminals.

A Potentiometer normally has a knob, slider or screw that lets you adjust the resistance between the terminals.

There are 2 ways a Potentiometer can work.

1. A Potentiometer can be used as something called a rheostat which is also a variable resistor like a Potentiometer. A Potentiometer uses only 2 pins for this.
2. A Potentiometer can be used as voltage divider which turns a larger voltage into a smaller one. A Potentiometer uses all 3 pins when used like this.

The way a Potentiometer works is similar a car window wiper. There is a small metal piece attached to the screw/knob/slider of the Potentiometer. This metal piece is touching a small strip of metal. Combining the metal piece and the metal strip creates resistance in a circuit.