Stroke sanders have a large sanding belt running horizontally over a surface that might be 8' long by 3' wide. A table below the belt holds the piece being sanded and a hand-controlled platen sits above the backside of the sanding belt (inside the moving belt). The sanding belt itself may be 6" to 12" wide. The operator moves the table holding the flat surface piece to be sanded in and out under the moving sanding belt. He then uses his fee hand to press the platen against the belt so that it contacts the surface of the material being sanded. This gives the operator control over sanding areas of a piece without removing too much material from the overall piece. The platen can be 6" square up to 1' x 3' or more.
Edge sanders have a large sanding belt mounted on a table continuously running but with the abrasive cutting surface facing the operator. Work pieces are held against the sanding belt to smooth out the piece. The operator can apply different amounts of pressure and movement to control the sanding and smooth out imperfections or create curves in wood.