Insulation is the ability to prevent energy from being transferred. There are three types of insulation: electrical, thermal, and sound.
 Electrical Insulation
Electrical insulation is common to most electrical devices. Proper insulation prevents the operator from being electrocuted, prevents short-circuits resulting from wires touching, and improves efficiency for energy being transferred over long distances. The most common type of electrical insulation is the rubber coating found on the outside of wire. Other materials used for electrical insulating include plastics, acrylics, ceramics, fibreglass, glass, nylon, polyester, PVC, and Teflon.
 Thermal Insulation
Thermal insulation is used to regulate the temperature of buildings, vehicles, and countless other applications. Thermal insulation conserves energy by reducing heat loss or gain. In industry, thermal insulation is used to facilitate the temperature control of a process or to transport temperature-sensitive goods. Materials used as thermal insulators include calcium silicate, glass, rock, perlite, plastic foam, and cement.
 Sound Insulation
Sound insulation is used to bring noise levels down to a level suitable for human senses. In industry, sound insulation is used in the cabs of machinery to protect the operator from continuous high levels of noise. Common sound insulating materials are melamine foam, polyurethane foam, glass, rubber, cork, wood, cement, fibreglass, and cellulose.