As with all computer programs, something will occasionally go wrong while you are working. Your work is the most valuable part of your computer so you really need to be prepared to be able to recover it in case something goes badly wrong on your machine.
People who grew up in the early days of the computer revolution automatically press CTRL+S (save current work) on their computers every couple of minutes, no matter what program they are working. This is still a very good habit than can protect you from losing valuable work. We strongly recommend that you cultivate this "old-fashioned" habit. If you do, you will never need to use the rescue copy feature.