Every home has what is called the mains electricity, which is the general-purpose power supply of electricity. In order to access this power, homes feature plastic devices, called electrical outlets or sockets, which allow other devices or appliances to connect to the alternating current running through the structure. Other such devices that allow manipulation of the current include switches and dimmers, which allow one to cut off the power supply to a light bulb or lessen it and create a slightly darker room.

The electrical outlet can come in several different types, depending on the wiring schema and the voltage. The standard outlet is usually a 15-amp receptacle for common appliances, supplying 120 volts through either 2 or 3 holes to accommodate corresponding pins.

Ground fault circuit interrupters (GFCI) receptacles are placed in bathrooms, kitchens, or any other place that will endure wet or humid conditions. These electrical outlets are easily recognizable by their narrow slits and the single semi-circular hole. This hole is the “ground” while the left and right slits are the “neutral” and “hot”, respectively. The GFCI monitors any imbalances in the current as it flows from hot to neutral; if any of the current begins flowing into the ground, the breaker in the GFCI switches on the kills the electricity.

Receptacles for dryers have pins for either 120 or 240 volts. Current building codes require all new homes be built with 4-hole dryer outlets, which feed 240 volts.