This document provides an overview of computer numerical control (CNC) machines. It discusses the history and development of CNC machines. It then describes the typical components of a CNC machine like the controller, automated tool changer, and feedback devices. The document explains how CNC machines work through programming codes and different operating modes. It highlights advantages like increased productivity and consistency. Challenges like high costs and need for skilled operators are also noted. In conclusion, the document states that CNC machines provide automation and efficiency benefits for large-scale manufacturing compared to manual machines.