Wake On LAN
Introduction
Wake on LAN (WOL), or sometime they called Remote Wake Up, is an Ethernet computer networking standard that allows you to turn-on a power-off computer or wake-up a sleeping or hibernating computer from another location over a network connection. For example, you want to access your data on your computer at home while you are traveling, you can do that by enabling WOL on your home computer. WOL works by sending a special message or signal over a local area network (LAN) or a wide area network (WAN), such as the Internet, to trigger power-up of a computer on a private LAN.
Purposes
To save electric energy, most people don't want their computers to stay on all the time.