A manufacturing process that creates three-dimensional objects by adding material layer by layer, guided by digital 3D model data and building parts directly from materials such as plastics, metals, or resins. This technology is widely used in 3D printing for rapid prototyping, custom tooling, and the production of end-use parts. It is especially used in industry sectors such as aerospace, automotive, healthcare, and consumer products, where it enables complex designs, lightweight structures, and low-volume or personalized production.

By contrast, traditional subtractive methods remove material from a solid block.