In most homes and offices the mandated, usual voltage is 120 watts. Anything dramatically above this represents a power surge or power spike. The difference between a power surge and a power spike is one of timing. If a jump in electricity lasts as long as than three nanoseconds or longer, it's known as a surge. If it's under that, it's known as a spike. Both can harm your electrical household or office equipment. If you pour too much water into a bucket, it will overflow. If you were to suddenly overfill a plastic storage bag with soup it would burst. The same principle applies to electrical surges and spikes. There is simply too much electricity zooming around for your household appliances to handle. Your office computers, like the bucket or bag, will overflow and burst, resulting in very costly repairs, and, what's worse, the loss of all your data. It is possible to be nearly ruined by an electrical surge.
A power strip is a small unit that allows you to plug more than one instrument in at time. It connects to the outlet in your wall, and then you can plug in your TV, radio, lamp, etc., into it. Or, in the kitchen, your power strip could handle the combined plugs of your microwave, toaster, and blender. The voltage flows through the kitchen outlet, down through the power strip, and into your appliances.
The surge protector is built right into the power strip. If there is a sudden surge or spike of electricity, then, the power strip is equipped to handle it. The excess of power is diverted into power strip's grounding wire, and all is well.
Electrical surge protection is not invincible, however. In a lightning storm, for example, you should switch your computer off and unplug it. If lightning strikes nearby, it will create such a massive surge that no electrical surge protection will be able to protect your computer or computers from it. Another common cause of high electrical surges is the presence of large appliances and devices, such as ovens and elevators, which, when turned on and off, require a lot of energy in a sudden manner. Electrical surge protection is not only important for dramatic moments, when a sudden, extraordinarily strong voltage surge goes through; a constant, high, steady level of voltage can wear wiring down over time, and so sort of wear away at your appliances and gradually destroy them.
There are many ways for power surges to occur; so many, in fact, that it's just not realistic to expect to avoid all of them. For that reason, you should use your electrical surge protection primarily on expensive, sensitive, complicated items such as computers and DVD players. Lamps aren't as important; with a lamp, the worst thing you'd get in the case of a power surge is a burned out bulb. You'll want to make sure that your source of electrical surge protection has a light to show whether its ability to protect you from sudden surges is stable or waning. Electrical surge protection wears down with time, and will need to be replaced from time to time.