Definition - What does Insulation mean?
Insulation is the act of separating two conducting materials by using a non-conducting material to stop the flow of heat, electricity or sound from one conductor to another or a material that can be used to insulate. Examples of insulating material include fiberglass insulation which is used in wall interiors, wire or cable insulation to stop electricity conducting outside a wire or cable.
Safeopedia explains Insulation
Any metal is a good conductor and any non-metal is a good insulator with graphite being the single exception. Graphite conducts due to it's unusual molecular structure. Metals and non-metals can be determined in a periodic table of elements. Electrical wires are made of copper and insulated with PVC or "plastic" to prevent electrical shock and maintain a steady flow of electricity. Non-metal insulators can be used to keep a house warm in winter or cool in summer as well as reduce noise. Some kinds of insulation materials can be dangerous to human health or the environment such as fiberglass which can cause skin irritation or cancer if inhaled.