A household circuit consists of three wires: live wire (red), a neutral wire (black), and earth wire (green). Earth wire is used for safety purposes, any current leaked into appliances flows harmlessly to earth. Homes typically have several kinds of home wiring, including Electrical wiring for lighting and power distribution, permanently installed and portable devices, telephone, heating or ventilation system control, and increasingly for home theatre and computer networks. The circuits that are wired into a house by an electrician all start with wires coming in from power lines outside that are connected to a fuse and meter. The meters record how much electricity you use, and therefore you will be charged for that use of energy. The household circuit is an electrical system that controls the flows of electricity at our house. In our house, the more things that are turned on, the more current is requested. Most standard 120-volt household circuits in your home are (or should be) parallel circuits. Outlets, switches, and light fixtures are wired in such a way that the hot and neutral wires maintain a continuous circuit pathway independent from the individual devices that draw their power from the circuit.