Most 3D printers (and subtractive devices like CNC machines) use a programming language called G-code (not to be confused with the 1999 album by rapper Juvenile, the 2005 song by Geto Boys on their The Foundation album, or the album put out in 2008 by Korean rapper Eun Ji Won).
Whether you're new to 3D printing or an old hand, ZDNet's 3D Printing Discovery Series will help you understand and get the most out of this amazing, accessible technology.