What is Earthing system?

A ground is a conducting connection. whether intentional or accidental between an electrical circuit or equipment and earth or to come conducing body which serves in place of the earth.

Earthing system

An earthing is defined as a connection to the general mass of earth. The term 'ground' is used in electrical work to refer to the earth as the zero of potential. Actually, a ground consists of artificial connection to the earth. having a very low resistance. The resistance of ground is low, therefore maximum current flow through it. The principle of earthing is always followed in electrical installation for the following reasons. Every electric supply electric distribution system has one of its conductors connected to earth at some control point. Water mains and cable sheath's are the best grounds obtainable. The best connection main is obtained by welding or soldering the connecting wire so as to eliminate any possibility of the connection loosening or burning off.
The  earth rarely serves as a part of the return circuit. The I.E.E regulations require that every item of electrical apparatus and every conductor apparatus and every conductor operating at a voltage exceeding extra-low voltage must be effectively prevented by use of earthing. Earthing conductor's need to satisfy two main requirements, namely to be strong enough to withstand any mechanical damage and also to be of sufficiently low impendence to meet the need to carry an earth fault current without danger.
An efficient earthing arrangement is an essential part of every electrical system to guard against the effects of leakage currents. short circuit, etc. The protective devices in the circuit (e.g fuses or C.B's) must operate so as to disconnect the fault within the maximum times specified in the regulations. The term earthed is used in electrical work to refer is connected to earth or to some conducting body which serves in place of the earth. The practice of earthing any metal which may come into contact with a live conductor  means that the leaking current is offered a path of much lower resistance than the human body. which carries is away safely.
The term 'earth' includes any type of floor which is hygroscopic e.g concrete, quarry, marble or other stone tiles. I.E.E regulation DI states that every item of apparatus and every conductor shall be prevented from giving rise to earth leakage currents by all-insulated construction by double insulation, by isolation or by earthing of exposed metal parts.Grounding in interior wiring systems is done for safety purpose and two classes of ground are connected in a system is connected to ground.

Equipment grounding is the connection between non-current carrying motor frames metallic parts in electrical installation to earth. (e.g metallic conduit, switch boxes etc.) Solid grounding or effective grounding means that the neutral is directly connected to ground without any resistance, inductor or capacitor in between neutral and ground.