Cement board is a building material made from a mixture of cement and reinforcing fibers. It is commonly used as a backing for tiles in areas exposed to moisture, such as bathrooms and kitchens. Its durability and resistance to water make it an ideal choice for preventing mold and damage in these environments. Typically, cement board comes in large sheets that can be easily cut to size. It is often installed over wooden or metal studs and can be used in both residential and commercial construction. Popular brands of cement board include HardieBacker and Durock.