When you plug in your toys or appliances into an electrical outlet, there are two things you need to think about: electricity and safety. If you touch the electric parts without proper protection, you could get an electric shock. Since we don't want that to happen, we have double insulated cables!
Double insulation means having two layers of insulation to protect the wires in a cable. The first layer covers the wire itself, while the second layer surrounds the entire cable. This extra layer of insulation keeps the wires safe from the elements, like water or dust, that could damage them or cause a hazard.
Think of it like wearing two coats. The first coat protects your body from the cold, but if you accidentally step into a puddle, it will get wet and not protect you anymore. The second coat will keep you dry and keep the first coat insulated, so you stay warm and safe.
Double insulation is often used for small electrical devices like hairdryers, electric shavers, and handheld power tools. So, whenever you see the "double insulated" label on an electrical device, you can be sure that it has extra protection to prevent an electric shock.