Hibernation mode means that you can turn off the computer and be sure that when you return, all your work (including programs and documents that haven't been saved or closed) will be restored exactly as it was when you left. The contents of the memory are saved to the disk, the monitor and hard drive are turned off, which also saves energy and reduces wear on the computer. Generally speaking, the time required to bring a computer out of hibernation is longer than that needed to come out of standby mode, but hibernation consumes less power. If you often get interrupted during your work, such as in some secretarial jobs...