The machining accuracy will not be perfect if the machine table and toolhead are not set properly. When the sides are perpendicular, it is referred as squareness. Parallelism means the two sides are absolutely parallel to each other. Alignment is an arrangement in which the relative positions of the table, the jaws of the vise, the toolhead and the ram are perfect. The above setting of the table, work and the tool are done with the help of test bars and feeler gauges.