Earthing associated with current carrying
conductor is normally essential to the security
of the system and is generally known as system earthing,
while earthing of non-current carrying metal work and
conductor is essential to the safety of human."

Proper grounding is a kind of a great science of obtaining path for the dissipation of current in to the earth. Hence it is imperative to understand grounding fundamentals. Earthing is the physical bonding / connection of electrical / electronic equipments by a conductor to the earth. It is a known fact that earth composition is of a numerous material that are variously good & poor conductors of electricity but the earth considered a good conductor. For this reason and as a reference point, the earth's potential is assumed to be zero. When an object is grounded, it is thereby forced to assume the same zero potential as the earth. if in case of variation in the potential of the grounded object (higher / lower), current will pass through the grounding connection until the potential of the object and earth are the same.