The term 'Chimney Liner' refers to a lining that is installed inside a chimney to protect the structure from heat and corrosion. The liner also helps to prevent the buildup of SOOT, which is a black or dark brown residue that is created when fuel is burned. The SOOT is composed of tiny particles of carbon and other materials that can be hazardous if inhaled. A chimney liner helps to reduce the amount of SOOT that accumulates in the chimney, making it safer for those living in the home.