The slide potentiometer is a linear variable resistor with a total resistance of 10k. When you move the lever from one side to the other, its output voltage will range from 0 V to the VCC you apply. It has four pins, 3 of which are connected to VCC, GND and the ADC IN on the slide, while the remaining pin is connected to a red indicator LED. You can use the indicator LED to visually display the change on the potentiometer.