The UK mains electricity supply is about 230V - and it can kill if it is not used safely.
Electrical circuits, cables, plugs and appliances are designed to reduce the chances of receiving an electric shock.
The more electrical energy used, the greater the cost.
Electrical supplies can be direct current (d.c.) or alternating current (a.c.).
Wiring a plug
[ This page has been adapted from www.bbc.co.uk/schools/gcsebitesize/science