Abrasives are materials used to wear away the surface of other materials through friction. They can be natural, like sand and diamond, or synthetic, such as aluminum oxide and silicon carbide. Commonly found in products like sandpaper and grinding wheels, abrasives are essential in various industries for tasks like polishing, cutting, and shaping. These materials are categorized into two main types: bonded and coated. Bonded abrasives are held together in a solid form, while coated abrasives have abrasive grains attached to a backing material. Both types are crucial for manufacturing, construction, and automotive applications, helping to achieve smooth finishes and precise dimensions.