A low pulse on this pin (below 1/3 of VCC) sets the internal flip-flop and makes the output go HIGH. When the voltage on this pin reaches 2/3 of VCC, it resets the flip-flop, and the output goes LOW.

Nowadays, visual indication is a must-have feature for any electronic device, which will make user interaction much easier. There are multiple ways to implement the visual indication, from simple ...