Connecting metal components of machinery and appliances with an earth plate or earth electrode, buried in moisturized earth (ground) through a thick conductor, is called earthing.

As the body or metal sheath potential of electrical appliances turns out to be zero (as earth potential for all practical purposes is treated zero), therefore any person or operator, who intentionally or unintentionally touches it, does not go through an electric shock.

Metal conduits, outer casings of the lead-covered wiring system, electric iron, table lamps, electric heater, and other household appliances connected with a metal tube, generators, motors, and metal frames of all other machines must essentially be earthed.