Even though every country in the world uses different types of plugs, the extraction of household power from a source remains more or less the same. The typical plug has two or three blades, or prongs, that are connected with wires inside the body of the plug. The blades become energized when inserted into a power outlet. Electricity flows through the blades and through the cord, therefore energizing the appliance connected.
When one blade is wider than the other it means the plug is polarized, which helps reduce the potential for shock. Three pronged plugs are polarized because they can only be inserted into a socket one way.
Older homes were not built with polarized power outlets. To avoid the risk of shock, it is important not to force a polarized plug into a non-polarized outlet. If a plug does not fit, a certified electrician can install a new outlet.
The use of extension cords can be dangerous if used improperly. Extension cords are always labeled with the size and wattage rating of the cord. Be sure to check the total amount of watts that will be connected to the cord prior to use. As a safety feature, most appliances and extension cords are made with polarized plugs. If a three-pronged plug does not fit into an outlet or extension cord, do not cut the grounding pin to insert the plug. If an extension cord is damaged, discard it. On a damaged or worn extension cord, even the smallest wire can cause shock or burn.