A variable resistor is a resistor in which the electric resistance value is adjustable. A variable resistor is an electromechanical transducer that generally works by sliding a contact (wiper) over a resistive element. A variable resistor is used because a potential divider with 3 terminals is known as a potentiometer. When it has two terminals, it acts as a variable resistor, which is known as a Rheostat. An electronically controlled variable resistor controls electronically instead of using mechanical action. This resistor is called a digital potentiometer.
