Advanced Configuration & Power Interface

Being an evolution of APM, ACPI is a technology that allows the operating system to automatically turn off computer peripherals in order to save energy. It was developed by the companies Hewlett-Packard, Intel, Microsoft, Phoenix and Toshiba initally to be used on notebooks in order to save battery. This standard was so successful that it became a desktop standard as well. It is available from Windows 98 on.

ACPI, together with ATX power supplies, allows the PC to be turned on or off based on computer events (even through the network) without pressing any hard switch. It is the ACPI standard that turns the PC off when we ask Windows to turn the computer off.