Each grain of sand on the sander or nook in the grinding stone takes off material. If either is run too quickly, the material will overheat and melt on the surface of the sander or grinder. There is no good way to remove the excess except to change the sand paper or break away bits of stone with a special tool. The important thing to know is that the rake angle helps determine the size and shape of the chip, and that specialized tools have certain requirements. The main advantages of a machine tool over a hand-held power tool are the rigidity of the machine and the precision of the operation.
Machines use their large weight and have thick iron supports to minimize flexibility.
Some shop machines have a guide that provide a path for the moving blade. There is less room for the blade to wander, and the cut is more precise. You should set this guide as close to the work piece as possible. A clamp holds the work piece in place and provides more rigidity in the machining process. You should set the clamp as close to the cutting position as geometry permits.