3D printing uses data from CAD programs to build three-dimensional objects layer by layer out of various materials. The document outlines several 3D printing technologies including PolyJet, Stereolithography, Fused Deposition Modeling, and Metal Laser Sintering, which differ in the materials used and how layers are deposited. These technologies are used across industries for prototyping, manufacturing, and production applications. The future of 3D printing is presented as continually evolving with innovations in areas like food printing, large-scale fabrication, automotive manufacturing, and bio-printing.