Alumina, also known as aluminum oxide, is a chemical compound made up of aluminum and oxygen. It is a white, powdery substance that is primarily used in the production of aluminum metal through the Bayer process. Alumina is also found in various forms, including hydrated alumina, which is used in water purification and as an abrasive material. In addition to its role in aluminum production, alumina has applications in ceramics, glass, and catalysts. Its high melting point and resistance to corrosion make it valuable in industrial processes. Overall, alumina is an essential material in many sectors, contributing to various technologies and products.