The document discusses additive manufacturing (AM) which involves building up a part layer by layer, unlike subtractive manufacturing which removes material. It describes three main types of manufacturing and focuses on AM. AM techniques build parts from 3D model data by joining materials together in successive layers, such as powder bed fusion which uses a laser. The document outlines advantages like reduced waste but also limitations including part size and material properties. It provides examples of common AM processes like fused deposition modeling and selective laser sintering.