In order to understand what is surge protection, first we need to know more about “Surge”. A power surge, or transient voltage, is an increase in voltage significantly above the designated level in a flow of electricity. In normal household and office wiring in the United States, the standard voltage is 120 volts. If the voltage rises above 120 volts, a surge protector helps to prevent the power strip from destroying your devices.
Power surges occur when something boosts the electrical charge at some point in the power lines. This causes an increase in the electrical potential energy, which can increase the current flowing to your wall outlet. The most familiar source is probably lightning. When lightning strikes near a power line, the electrical energy can boost electrical pressure by millions of volts.
If the surge or spike is high enough, it can inflict some heavy damage on devices. Approximately the same thing happens when too much electrical pressure runs through a wire -- the wire heats up and burst. Even if increased voltage doesn't immediately break your machine, it may put extra strain on the appliances and wear them down over time.