Final answer:
CNC machines are automated and controlled by computers, allowing them to execute pre-programmed commands with high precision, whereas manually operated machines require physical guidance by an operator.
Step-by-step explanation:
The main difference between CNC machines and manually operated machines is that CNC machines are automated and controlled by computers. Unlike manual machines, which require an operator's physical guidance to control machining tools, CNC (Computer Numerical Control) machines operate through a series of pre-programmed commands. These commands drive the action of the machine tools, enabling the production of parts with high precision and repeatability.
CNC machining is akin to a highly sophisticated assembly line where each CNC machine functions as a complex biochemical machine, executing specific tasks to contribute to the creation of a final product. The difference in comparison to a manual machine is that instead of an assembly line worker, a CNC machine has an internal 'brain' in the form of a computer that follows exact trajectories, operates tools, and makes decisions based on coded instructions.
This level of automation and precision allows for complex shapes, dimensions, and patterns to be manufactured with great accuracy, which would be extremely difficult, if not impossible, to achieve with manual operation. As a result, industries that demand high precision and efficiency often rely on CNC technology to produce components for various applications, from aerospace to automotives and consumer electronics.