Stand by is a feature of computer operating system that allows to switch computer to
ACPI G1 Sleeping S3 state. Stand by term is usually used in
Microsoft Windows OS and applies to all G1 Sleeping states except S4 (Hibernation). If the computer has power management support, the user can stand by the computer by going to
Start -> Shutdown and then choose Stand by. When the computer stands by, the monitors and hard disks turn off and the
CPU runs on low power, but the whole system is still running with the session stored to the memory. Stand by is most widely used on laptops and other portable PCs.
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