An angle grinder is a versatile power tool used for grinding, cutting, polishing, and sanding a variety of materials such as metal, stone, concrete, and ceramics. It features a rotating disc or wheel that can be easily swapped for different attachments depending on the task. Angle grinders are commonly used in construction, welding, and metalworking for tasks like smoothing rough edges, removing rust, or cutting through tough materials. They come in various sizes and power options, making them suitable for both professional and DIY use.