hibernation mode - technical definition

A power-down mode in a portable computer that provides a quicker resumption of operation than normal when turned back on. When hibernation mode is activated, all current applications running in memory are saved to disk, and the computer is turned off. When resuming, the former state of memory is read from disk, and the computer appears exactly as it did before hibernation. Hibernation causes no drain on the battery. Contrast with standby mode.