A Universal milling machine is a traditional, mechanically-controlled milling machine that is operated by a skilled machinist. It uses hand wheels and levers to control the movement of the cutting tool and the workpiece, and it is typically limited to performing one operation at a time. A CNC (computer numerical control) Vertical Machining Center (VMC) is a type of CNC milling machine that is characterized by its vertical orientation and its use of a spindle that moves in the z-axis (up and down). The cutting tool and workpiece movement are controlled by the CNC system, which can execute a series of instructions programmed into it, allowing for automated and precise control of multiple operations.

The main difference between a Universal milling machine and a CNC Vertical Machining Center is the level of automation and precision that each is capable of. With a Universal milling machine, the machinist is required to manually control the cutting tool and workpiece movement, which can be more time-consuming and less precise than with a CNC VMC. With a CNC VMC, the cutting tool and workpiece movement are controlled by a computer program, which can execute a series of instructions with much greater speed and accuracy, allowing for more complex and efficient machining operations. Additionally, CNC VMCs tend to have larger work envelopes than Universal mills, with more travels along x,y,z axis and can be equipped with tool changer for automation. Also CNC VMCs can be used for 3D surface machining and contouring, whereas Universal mill is limited to 2D machining.