The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?

Plastic or rubber is an insulator which does not allow the electric current to pass through it. Thus, the handles of the tools like screwdrivers and pliers used by electricians for repair usually have covering of plastic or rubber, so that electric current may not pass through these tools to the electrician’s body to harm him. Hence, they protect against electric shock.