The debounce method takes a duration and returns an instance of the Observable class that only emits a value if a time frame that is equal to the passed time from the moment when the previous value was emitted. The following diagram explains how this works: 

The preceding diagram shows how the debounce method reduces events. The debounce method takes a time frame and returns a new instance of the Observable type that only emits the last value that was produced during this timeframe.