Some materials conduct electricity and others block it. Materials that allow electric current to flow are called Conductors. Aluminum, brass, copper, silver, gold and water make good conductors. Materials that do not conduct electricity are insulators or non-conductors. Glass, rubber, and plastics are good insulators.
Electricity flows only when the circuit is complete.
When the path is broken, the electricity stops. Electricity cannot flow through the gap in the path. This is called an open circuit. When a light switch is turned on, the circuit is closed. Turning the switch off opens the circuit.