Potentiometers are also commonly called 'pots' and sometimes referred to as variable resistors. A typical potentiometer has three leads. Potentiometers are often used as volume controls on audio equipment. Trimmer potentiometers (sometimes called trimmer pots) are not adjusted as often as a potentiometer would be and are much smaller in size.
A potentiometer is also called a rheostat. It is a resistance with a wiper that can be positioned according to the needs of the circuit. By positioning the wiper suitably, the resistance in the circuit is increased or decreased, causing the current flowing through the circuit to be controlled to a specific desired level.
Typically a potentiometer or “pot” as it is commonly called, finds application in electronic equipment for voltage control. Potentiometers come in various sizes depending on the application. Very small ones are called trimmer potentiometers. Most potentiometers usually come with three leads, of which one is common to both output and input and the other two leads are for input and output.