The role of potentiometer summed up for the following three points:

First, the control current: When the selected current output terminal is sliding contact terminal, the digital rotary potentiometer can be used to control the current.
The second role, the partial pressure: that is assigned to the partial voltage, when the potentiometer sliding or rotary handle to adjust the moving contact slip. The output of the potentiometer can be obtained with the potentiometer voltage and stroke into a certain relationship between the output voltage.
The third role: to change the resistance: When the potentiometer connected into two devices, the Linear Conductive Plastic Potentiometer in the stroke range can be a smooth continuous change in the resistance value, then the potentiometer is to play a role in changing the resistance.