program is used to send Wake on LAN (WoL) frames over a local Ethernet network to one or more hosts using their link layer (hardware) addresses. WoL functionality is generally enabled in a machine's BIOS and can be used to power on machines from a remote system without having physical access to them.
interface is an Ethernet interface of the local machine and is used to send the Wake on LAN frames over it. If there is only one Ethernet device available that is up and running, then the interface argument can be omitted. lladdr is the link layer address of the remote machine. This can be specified as the actual hardware address (six hexadecimal numbers separated by colons) or as a hostname entry in /etc/ethers. wake accepts multiple lladdr addresses. Link layer addresses can be determined and set using ifconfig(8).