Dimethicone in its simplest form is polydimethylsiloxane, also known as silicone oil, but more commonly called dimethicone. Silicone oils are derived from silica (sand and quartz are silicas).
Dimethicone comes in various viscosities, this one is 1000 centistokes, a medium viscosity which offers excellent barrier properties when used in skin protectant formulations. It adds slip and glide, reducing tackiness. It offers conditioning properties when used in hair and skin care applications.