Abrasive discs, wheels, and paper are all designed for sanding, grinding, finishing and stripping materials. The type of abrasive you need will depend on the size of your project and the material you are working on. Discs have one side of abrasive particles and one side of a soft material, usually cloth or sponge that can be used for polishing. Grinding Wheels are attached to a grinding machine that can cut, sand, grind and polish the same as an Abrasive Disc, but on a much larger scale. Abrasive Paper, more commonly known as sandpaper, can be affixed to handheld power tools or used by hand for small projects. It is commonly used for removing old layers of paint, finishing wood, or to roughen a surface as in preparation.