The wires you use to make electrical circuits contain long strands of copper that are twisted together. When the wire is in a circuit and the switch is closed (turned on), electricity flows through the strands. The plastic coat around the copper strands is an insulator. It stops the current passing to other objects that the wire may touch.

Copper is used in the wire because it is a good conductor of electricity and, like all metals, it is flexible. However you should not bend the wires too often as the strands can then break.

The wire you may use in class may be made from a single strand of copper. This is used for low-voltage circuits.