When you press the trigger button, the 555 timer outputs a single pulse of fixed duration.
This is perfect for debouncing mechanical switches, which can create multiple unwanted pulses
due to contact bounce. The pulse duration is determined by the resistor and capacitor values.
Pulse Duration (T) = 1.1 × R × C
In Ben Eater's computer clock, this ensures one button press = one clean clock pulse,
preventing the computer from executing multiple unintended steps.