About 3D Printing
3d printing, also called additive manufacturing, is distinct from other manufacturing processes. During an additive process, material is deposited layer-by-layer. There are a variety of processes, but the current low-cost machines typically work like glorified robotic glue-guns, laying down paths of melted plastic one layer at a time. Digital manufacturing is any computer controlled manufacturing technique that enables the production of digital models made with CAD software. Digital manufacturing methods include both additive and subtractive (where material is removed) processes.
About Open Source Hardware
As defined by the Open Source Hardware Association:
Open source hardware is hardware whose design is made publicly available so that anyone can study, modify, distribute, make, and sell the design or hardware based on that design. The hardware’s source, the design from which it is made, is available in the preferred format for making modifications to it. Ideally, open source hardware uses readily-available components and materials, standard processes, open infrastructure, unrestricted content, and open-source design tools to maximize the ability of individuals to make and use hardware. Open source hardware gives people the freedom to control their technology while sharing knowledge and encouraging commerce through the open exchange of designs.