Sanding discs are circular tools used in woodworking and metalworking to smooth surfaces or remove material. They are typically made of abrasive materials, such as aluminum oxide or silicon carbide, and come in various grits, which determine their coarseness. Sanding discs can be attached to power tools like orbital sanders or angle grinders for efficient sanding. These discs are available in different sizes to fit various machines and applications. Users can choose from hook-and-loop or adhesive-backed options for easy attachment and removal. Proper selection of grit and type is essential for achieving the desired finish on materials like wood, metal, or plastic.