Insulation

n.
  1. The act of insulating, or the state of being insulated; detachment from other objects; isolation.
  2. (Elec. & Thermotics) The act of separating a body from others by nonconductors, so as to prevent the transfer of electricity or of heat; also, the state of a body so separated.
  3. The material or substance used to insulate from either electrical or thermal conduction; as, fiberglass is used as thermal insulation in the walls and roofs of houses.