What is the difference between a potential divider and a potentiometer?
simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. (a) A potential divider. (b) A potentiometer.


A potential divider is made of two resistances, usually fixed. 
A potentiometer is a resistor with an adjustable tap-off point. It performs the same function as the potential divider but can be varied without replacing components.


The output voltage is a function of the resistance values each side of the tap-off and the voltages at each end. The load being driven by the divider will also affect the divider voltage.