Note: Doze is no longer under development, and it is no longer available for download.
While Doze is running, it will prevent your system from going to sleep. Consider a time when you leave your computer running to finish a download and your computer falls into sleep-mode before it finishes. Perhaps you're reading something while running off the battery and your monitor keeps dimming. By running Doze it will appear as if there is constant activity on your system without using any CPU.