GFCI, or Ground Fault Circuit Interrupter, outlets are a safety device that helps to protect people and devices from electrical hazards. By using a sensor to monitor the flow of electricity, a GFCI will shut off power to the outlet when it detects an irregular or inconsistent flow of electricity. They should be found within 6 feet of areas where water and electricity can be in the same place, such as outlets by counters in bathrooms and kitchens. GFCI's should also be used on the exterior of the home, where rain may impact a plugged in appliance.
Electricity is a vital utility to our day-to-day lives, but can be very dangerous when not handled properly. In the event of a hazardous condition, such as water splashing across a hairdryer being used in the bathroom, it may be possible for someone to come in contact with electricity, allowing it to flow though their body instead of just the wire. This can lead to many levels of injury that could mean anything from a small shock or to a trip to the hospital. GFCI outlets will cut off the flow of electricity before it can cause harm, making it a cheap and easy safety that can be life-saving.
When a GFCI outlet is installed in a circuit, all outlets downstream on that circuit will be protected. For example, a kitchen may have six total outlets, but only one the outlet next to the sink is a GFCI. The other outlets are also on the same circuit in the kitchen, so if any one of them experiences a hazard, power to all six will shut off. However, the bathroom next to the kitchen will still have power. This is because it is on a separate, bathroom circuit and should have its own GFCI outlet. Commonly, multiple bathrooms will be on the same circuit, so if one bathroom experiences a hazard, power will be shut off to the other bathrooms sharing that circuit.