"The goal of Fast Boot is pretty obvious from its name - Windows 8 boots up faster than previous versions of the operating system ever did. To accomplish this feat, Windows 8 doesn't totally shut down when you click the Shut down command. Instead it only partially shuts down and partially hibernates. This is the Hybrid Shutdown part of the equation. Then, when you turn on your computer, Windows 8 starts very quickly because it only has to partially boot up and partially wake up. This is the Fast Boot part of the equation. Fast Boot also gets a boost from the efficiency of today's hardware; namely UEFI (Unified Extensible Firmware Interface) and multi-core processors."
Lényegében tényleg erről van szó.