S0 - On / Working
The computer is powered up. If supported, power conservation is handled
by each device.
S1 - Sleep
CPU is stopped. RAM maintains power. Everything else is off, or in low
S2 - Sleep
CPU has no power. RAM maintains power. Everything else is off, or in
low power mode.
S3 - Standby
CPU has no power. RAM maintains power, refreshes slowly. Power supply
reduces power. This level might be referred to as “Save to RAM.” Windows
enters this level when in standby.
S4 - Hibernate
Power to most hardware is shut off. Any files in memory are saved to
the hard disk in a temporary file. If configured, the NIC will remain
on for WOL, or AoL. This level is also known as “Save to disk.”
S5 - Off
Everything is off. No files are saved. If configured, the NIC will maintain
power to listen for WOL (Magic) packets. This is known as a shutdown.