A potentiometer is an electrical component that allows users to adjust resistance in a circuit. It typically consists of a three-terminal device with a resistive element and a movable contact, known as a wiper. By turning the knob or sliding the lever, the user can change the resistance, which in turn alters the voltage or current flowing through the circuit. Potentiometers are commonly used in various applications, such as volume controls in audio equipment and brightness adjustments in LED lights. They can be found in both analog and digital devices, making them versatile components in electronics.