Numerical control technology refers to the technology of using numerical instructions composed of numbers, text, and symbols to control the movement of one or more mechanical equipment. Numerical control is generally achieved through the use of general-purpose or specialized computers for digital program control, hence CNC, also known as Computerized Numerical Control (CNC), is commonly referred to as CNC in foreign countries, and the concept of NC is rarely used again.

The determination of the process requirements for typical parts and the batch size of processed workpieces, as well as the formulation of the functions that CNC lathes should have, is a prerequisite for preparing in the early stage and selecting CNC lathes reasonably: meeting the process requirements of typical parts.

Most turn-milling composite machining is completed on a turning center, while the general turning center only replaces the ordinary turret tool holder of a CNC lathe with a turret tool holder with a power tool, and the spindle adds a C-axis function. Due to limitations in the structure and overall dimensions of the turret tool holder, the power of the power head is low, the rotational speed is not high, and larger tools cannot be installed. This type of turning center is mainly for turning, and the milling and drilling functions are only for auxiliary processing. The high cost of power tool holders results in high costs for turning centers

The turning and milling composite machining center is a machine tool with B-axis linkage and C-axis linkage that can perform turning and milling processing. It can be said that all or most of the processing of a part can be completed on the turning and milling composite machine tool, so it is also known as a small production line. It not only improves the accuracy of products and the efficiency of processing products, but also greatly saves the floor space of machine tools for enterprises. In the past, it was necessary to complete the processing of a part on several machine tools, but now only one machine is needed to complete all the processing.

The overall price of ordinary machine tools is relatively cheap, making them more cost-effective in terms of production costs. The main advantage of ordinary machine tools is experience, and experienced operators who have received training on ordinary machine tools will excel in machining efficiency compared to novices using CNC.