Editing Advanced Power Management (section)

==Power states==
The APM specification defines system power states and device power states.

===System power states===
APM defines five power states for the computer system:
* Full On: The computer is powered on, and no devices are in a power saving mode.
* APM Enabled: The computer is powered on, and APM is controlling device power management as needed.
* APM Standby: Most devices are in their low-power state, the CPU is slowed or stopped, and the system state is saved. The computer can be returned to its former state quickly (in response to activity such as the user pressing a key on the keyboard).
* APM Suspend: Most devices are powered off, but the system state is saved. The computer can be returned to its former state, but takes a relatively long time. (Hibernation is a special form of the APM Suspend state).
* Off: The computer is turned off.

===Device power states===
APM also defines power states that APM-aware hardware can implement. There is no requirement that an APM-aware device implement all states.

The four states are:
* Device On: The device is in full power mode.
* Device Power Managed: The device is still powered on, but some functions may not be available, or may have reduced performance.
* Device Low Power: The device is not working. Power is maintained so that the device may be 'woken up'.
* Device Off: The device is powered off.