What is the advantages of variable resistor?

When we want to regulate somthing ;we use variable resistors for example :volume control in radiOS and volume in headset. Also , the variable resistors can forms a potential devider in which the overall resistance between the two end points remain the same,but the ratio of the two resistors in the legs changes.so the variable resistor is affectively a potential divider.

Also, the variable resistor can forms a potential divider in which the overall resistance between the two end points remains the same, but the ratio of the two resistors in the legs changes. So, the variable resistor is effectively a potential divider.