What Does Advanced Power Management (APM) Mean?
Advanced Power Management (APM) is an application programming interface (API) developed jointly by Microsoft and Intel. It allows an operating system to communicate with the computer’s BIOS in order to achieve efficient power management.
The first version was released in 1992 and the latest APM specification was Revision 1.2 released in 2006. Microsoft discontinued support for APM starting with Windows Vista in favor of the advanced configuration and power interface (ACPI).
Techopedia Explains Advanced Power Management (APM)
APM is a layered approach in device management. From the top, APM-aware applications and programs such as device drivers communicate with the OS’s APM driver. This driver then communicates to the APM-aware BIOS, which controls the hardware and is then able to make changes according to the requests sent from the top.
Communication is bi-directional, meaning that power management events are relayed from the BIOS to the OS APM driver, and the APM driver can send requests to the BIOS through function calls.
The APM driver simply acts as an intermediary between the OS and BIOS. Power management can occur through power state change requests or automatically through set parameters based on device activity.