CNC machining is a reduced-material manufacturing technique that uses machine tools and tools to cut or carve the desired shape from the original material. 3D printing is an additive manufacturing technique that uses print heads to stack materials layer by layer to build three-dimensional objects based on computer-aided design (CAD) models.

CNC machining can use a variety of materials, such as metal, plastic, wood, etc., while 3D printing mainly uses plastic and some metals. CNC machining can make parts of various sizes, while 3D printing is limited by the size of the printing bed.

CNC machining is generally faster than 3D printing, but requires pre-programmed tool paths and parameters. 3D printing is slower, but only requires slicing software to convert the CAD model into G code. The precision and surface quality of CNC machining is generally higher than that of 3D printing, but it also produces more waste. The cost of CNC machining and 3D printing depends on a variety of factors such as material, quantity, complexity, post-processing, and more. In general, CNC machining is more cost-effective for parts that are produced in large batches or require high precision, while 3D printing is more advantageous for parts that are produced in small batches or with complex shapes. CNC machining and 3D printing also have different applications. CNC machining is suitable for the manufacture of durable, precise and heat-resistant parts, such as mechanical parts, molds, fixtures, etc. 3D printing is suitable for manufacturing complex, lightweight and personalized parts such as prototypes, artwork, toys and more.