(一)Additive VS Subtractive

◆CNC machining works by taking a material mass and subtracting from it to create a unique part versus 3D printing works from building up materials from nothing to build a part. CNC routers work by using computer-aided design software (CAD) to create a blueprint of a particular part, and then proceed with creating that blueprinted part by using computer-aided manufacturing software (CAM) to cut away at a portion of material. This process, simply put, is subtractive where the finished result is a refined part that is comprised of less material then it had in its unrefined state. 

◆The 3D printer is different in that it works in the opposite direction. it creates parts by adding layers of material until the end product is formed. 

（二）Rapid Prototyping VS Mass Production

◆The CNC machining is a significant industrial tool for large scale and scalable mass production. It can create large dense products for high tech machinery with great efficiency.

◆3D print are more suited for domestic, creative and medical purposes with rapid prototyping. Without the scalability of being able to produce a large quantity of products at a time, printers are lending themselves to individually-produced items, which is ideal for the customized consumer industry. They can create small industrial parts but its inability to mass produce means it’s better for personal domestic creativity, and household desires, such as unique gifts, custom iPhone cases, art pieces and more.