Wake-on-LAN is platform-independent, so any application on any platform that sends magic packets can wake up computers running on any platform. It is not restricted to LAN (Local area network) traffic.
The computer to be woken is shut down (sleeping, hibernating, or soft off; i.e., ACPI state G1 or G2), with power reserved for the network card, but not disconnected from its power source. The network card listens for a specific packet containing its MAC address, called the magic packet, broadcast on the broadcast address for that particular subnet (or an entire LAN, though this requires special hardware or configuration).
The magic packet is sent on the data link or layer 2 in the OSI model and broadcast to all NICs within the network of the broadcast address; the IP-address (layer 3 in the OSI model) is not used.
When the listening computer receives this packet, the network card checks the packet for the correct information. If the magic packet is valid, the network card takes the computer out of hibernation or standby, or starts it up.
In order for Wake-on-LAN to work, parts of the network interface need to stay on. This consumes standby power, which is less power compared to the computer's normal operating power. If Wake-on-LAN is not needed, disabling it may reduce power consumption while the computer is switched off but still plugged in.[4]