A sander is a power tool used to smooth surfaces by abrasion with sandpaper. Sanders have a means to attach the sandpaper and a mechanism to move it rapidly contained within a housing with means to handhold it or fix it to a workbench. Woodworking sanders are usually powered electrically, and those used in auto-body repair work are usually powered by compressed air. There are many different types of sanders for different purposes. Multipurpose power tools and electric drills may have sander attachments. Types.
https://en.wikipedia.org/wiki/Sander