Insulation / Insulate / Insulated / Insulating
The term insulation when used in reference to electrical wiring is a material used to block the flow of electricity. Insulation can cover a wire or when covering multiple wires is referred to as sheathing. Insulation blocks the flow of electricity, but also serves the purpose of protecting wires from physical damage. You will also see insulated products like tools, shoes, and gloves. Things that are insulated are coated or cover with an insulator.