The term debounce comes from the hardware world. When you press a physical button it's common place for the contact to bounce, causing the contact to open and c

The term debounce comes from the hardware world. When you press a physical button it's common place for the contact to bounce, causing the contact to open and close a few times in rapid succession. So you, debounce the button press to ensure that it only causes one edge or press to propagate to the rest of the circuit.