Professional Answer: Earthing, also known as grounding, is a critical safety measure in any electrical installation. Its fundamental purpose is to create a low-resistance path for fault currents to safely flow into the earth. This prevents dangerous voltages from building up on equipment casings and metal enclosures, thus protecting personnel from electric shock and safeguarding electrical equipment from damage. It ensures a stable reference point for the electrical system and helps protective devices, such as fuses and circuit breakers, to operate effectively.