A potentiometer or a "pot" is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used, it acts as a variable resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment.
Potentiometers are often used to adjust the level of analog signals such as volume controls on audio equipment, and as control inputs for electronic circuits such as light dimmers. The applications of potentiometers include audio control, television picture brightness, contrast, and color response control, displacement transducers, analog function generators.
Based on the construction, the cross-section property of resistive element to be more specific, a potentiometer can be Linear taper potentiometer whcih has constant cross-section or Logarithmic potentiometer which has tapered cross-section. Another form of potentiometer is called rheostat, a two-terminal variable resistor. Other potentiometers include Digital potentiometers and Membrane Potentiometers.