There can be several motivations to do this save on power, save on the environment, save on wear-and-tear of your equipment, etc. WOL is probably most commonly used to wake up a server or NAS, just before access to these machines is needed – for example a media server, which can sleep all day long until you want to watch a movie. This means for example your home network. Wake On LAN, or WOL, is a Ethernet standard that allows you to “wake up” computers or network devices that are in stand-by, and is originally intended for use in a local network.
3 Power Management - Standby and Wake Up.