Potentiometers come in different types.
Rotary and trimpot potentiometers are wire wound, and are single or multi-turn, depending on the number of times the knob may be turned. The resistance is lowered or increased by turning the knob clock or counterclockwise, where the knob direction is dependent on the end that is used with the wiper.
Faders or sliders as they are also known, have a rectangular shape, and the wiper moves back and forth in a linear fashion.
How does a potentiometer work?
Potentiometers work by having a resistive element inside. Both end terminals are attached to it, and do not move. The wiper travels along the strip when the knob is turned. The closer the wiper is to the end terminal it is wired in conjunction with, the less the resistance, because the path of the current will be shorter. The further away it moves from the terminal, the greater the resistance will be.
The symbol for a potentiometer is the same one as a resistor, save for an arrow in the middle. In a circuit where they are used strictly as variable resistors or rheostats, only two terminals are wired to the other components. All three terminals are wired separately when they function as voltage dividers. Light dimmers in houses and volume controls on electronics are two common applications. Others include switches and position sensors.