A silicone or polysiloxane is a polymer composed of repeating units of siloxane (−O−SiR2−O−SiR2−, where "R" stands for an organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, grease, rubber, resin, and caulk. From the chemical perspective, silicones are unusual because they feature inorganic backbones, composed only of Si and O, but they have properties of organic polymers. They represent one of the main applications of organosilicon chemistry.
Silicone is often confused with one of its constituent elements, silicon. Silicon, a hard gray solid, is used to make integrated circuits ("electronic chips") and solar cells. In contrast, silicones, which tend to be electrical insulators, are often colorless oils or rubbery resin.
