Take a look at the circuit shown. The multivibrator is now using the resistor R4 and the capacitor C1 as coupling elements.
Connecting the battery, LED2 lights up. As long as you are not touching the push-button switch, it stays that way. The state is stable.
By pressing the push-button switch S1, LED2 goes out and LED1 lights up.
But now something new happens. The LED1 lights only for a few seconds and the multivibrator falls back to its stable state.
This circuit is also known as a Monoflop, Univibrator or Oneshot.
But how does this circuit work...?