CNC stands for Computer Numerical Control
It is a flexible system that allows you to control the movement of tools and workpiece through computer programs that use numeric data.
The basic classification of the CNC machines are Turning center and Machining Center.
Turning Center :
The CNC machine which works on the principle of lathe machine is identified as Turning Center. Similar to a lathe machine here the Workpiece is rotated and tool is moved. Turning center specializes in machining process like Turning, Facing, Taper turning, boring, grooving, threading etc
The CNC machine which works on the principle of milling machine is identified as Machining center. Similar to a Milling machine here the tool is rotated and workpiece is moved. Machining center is further classified into Vertical Machining Center (VMC) and Horizontal Machining Center (HMC) based on the orientation of the machine spindle. If the machine spindle is aligned in vertical direction in a machine, the machine is identified as Vertical Machining Center. If the machine spindle is aligned in horizontal direction in a machine, the machine is identified as Horizontal Machining Center.
Machining Center specializes in Milling, Facing, drilling, boring, tapping, slot machining, pocket machining etc.
In addition to the basic classifications the Computer Numeric Control machines are also identified as Turnmill centers. As the name implies this category of machine is an hybrid of Turning Center and Machining Center. This means the Machine has the capability to rotate the workpiece and also to rotate the tool what ever is required. In physical appearance the machine looks like a Turning Center.
Recommended Books to read about Computer Numeric Control machines: