Surge protector in simple language you call it a spike Guard
Also known as a surge suppressor, a surge protector is a plug-in device that is designed to help protect the computer from surges and spikes . To the right is an image of a Belkin power strip and surge protector. As can be seen, this power strip not only helps protect the devices connected to it, but also allows eight additional devices to be connected to one outlet.
Underwriters Laboratories produced a standard that governs surge suppressors called UL 1449, which defines the surge suppressor offers protection well beyond the power supply found in your computer.
While it is important to protect your computer and computer peripherals, it is also important to protect your computer modem and network card. Surges not only have the capability of traveling over the power lines, they can come over any line that's coming from outside your home or buisness.