An angle grinder, also known as a side grinder or disc grinder, is a handheld power tool used for grinding and polishing. Although developed originally as tools for rigid abrasive discs, the availability of an interchangeable power source has encouraged their use with a wide variety of cutters and attachments.

A power tool is a tool that is actuated by an additional power source and mechanism other than the solely manual labor used with hand tools. The most common types of power tools use electric motors. Internal combustion engines and compressed air are also commonly used. Tools directly driven by animal power are not generally considered power tools. Power tools can produce large amounts of particulates, including ultrafine particles. Airborne particulate matter is a Group 1 carcinogen.