The UK mains electricity supply is about 230V and can kill if not used safely. Electrical circuits, cables, plugs and appliances are designed to reduce the chances of receiving an electric shock. The more electrical energy use the greater the cost.
Electrical supplies can be direct current (d.c.) or alternating current ( a.c. ). You should know the colour coding for electrical wires and the function of each wire.
A mains electricity cable contains two or three inner wires.
If you are in any doubt whatsoever when wiring plugs or replacing fuses, stop what you are doing and get expert advice.
UK electrical wiring colours have changed in the past so it is essential you can tell difference between old wiring colours and new colours. IET Wiring Regulations), currently in its 17th edition Amendment which provide the detailed descriptions referred to by legislation. You should also note that the official voltage for mains electricity in the UK is 230V, although it is often referred to as 240V.