The electricity we use in modern society is artificially generated at power stations. Leaving the station at high voltages, it is then progressively 'stepped down' by means of transformers to voltages we can use in the home and workplace. Cables conduct electricity, either overhead or underground, to the walls, ceilings and floors of our factories, offices and homes, to operate the machinery, lights and appliances within. A cable conducting electricity becomes 'live' if the insulating cover of the cable is ruptured, the bare wire then becomes dangerous to touch as it will conduct electricity - by physical touch - into our body tissues. Depending on the voltage, this will produce effects ranging from a 'startle' response to burn, shock or electrocution.