The Class of an appliance is determined by the level of danger it poses to the user, divided into three categories: Class 1, Class 2, and Class 3. Class 1 appliances have limited insulation and require an earth for safety. Examples include freezers, irons, photocopiers, and microwaves. Class 2 appliances have enhanced insulation and do not require an earth, making them safer. Examples include lawn mowers, TVs, lamps, and drills. Class 3 appliances operate at low voltage and pose the least risk, though their charging leads may need testing. Examples include laptops, phone chargers, and cameras.