* Insulators prevent the flow of electricity. They are materials that resist the movement of electric charge.

* Conductors allow electricity to flow easily through them.

The cover of a plug is designed to protect you from electric shock. It's made of a material that won't conduct electricity, keeping the live wires inside the plug isolated from you.

Here's an analogy: Imagine a plug as a house with a live wire inside representing a dangerous room. The cover acts as a wall, preventing you from accidentally entering the room and getting hurt.