When using a drilling machine, you need to move the cutting attachment in a vertical motion to pierce and remove parts of the workpiece. Milling machines, on one hand, utilizes either a horizontal or vertical motion to bore holes, fine-tune edges or cut specific shapes.  Drilling is that drilling is a process of making a hole into a solid surface. While, milling is a process where you create features like slots, walls, fins, webs, etc. Here are some of the major differences between milling and drilling: Drilling uses vertical motions with a rotating drill bit to create holes in a job. Turning operations are operations that rotate the workpiece as the primary method of moving metal against the cutting tool. Lathes are the principal machine tool used in turning. Milling operations are operations in which the cutting tool rotates to bring cutting edges to bear against the workpiece.