Potentiometers are very useful in changing the electrical parameters of a system. It is a resistive type potentiometer which you can use to change RC constant of a circuit, changing the voltage level at comparator, changing the audio output volume, changing the brightness of any LCD screen, even measuring the rotary movement if it is used as a transducer, controlling the precise movement of servo motors and other control applications.
A Trimpot is another type of potentiometer that comes in small package. It has three leads and can be easily mounted on breadboard or perf board for quick prototyping. The value of the pot can changed by varying the knob on top of it.
500K Ohm Linear Taper...
WX050 10K OHM 5W...