Imagine this situation: you started working on a presentation, saved it couple of times, then got so much involved in your work that you spent an inordinate amount of time working on it without saving it. Then, your computer unexpectedly crashes or just shuts off due to some unexpected crisis. Or maybe just PowerPoint crashes for some reason. Does it mean you are now left with your presentation in the status when you last saved it and lost all your work? Not really because you can restart PowerPoint, and one of two occurrences may happen.