= Digital fabrication is the art of using computers to describe physical objects and using genetics, robotics and nanotechnology (GNR) to create them. 
= The making of physical objects through the use of computer-controlled tools. 
"Digital fabrication is the use of computer-controlled fabrication, as instructed by data files that generate tool motions for fabrication operations. Digital fabrication is an emerging byproduct of the computer age. It is becoming more accessible for small scale production, especially as the influence of open source philosophy is releasing much of the know-how into non-proprietary hands. For example, the Multimachine is an open source mill-drill-lathe by itself, but combined with computer numerical control (CNC) of the workpiece table, it becomes a digital fabrication device."
"Digital fabrication requires a relatively complex set of operations to accomplish. First, a digital model is created using specialized software. The geometric information from the digital model is then translated into instructions for tool paths and related tooling information. Any tooling or material setup is readied, and the instructions are communicated to the tool and then run. Each type of computer controlled tool has its own specific approach, but most rely on a robotic head that traverses a spatial grid based on coordinate instructions, and which deposits, cuts, or otherwise manipulates material.
Digital fabrication tools are categorized by the manner in which they are controlled and the way in which they manipulate materials. These categories are not always clearly bounded and there is overlap where tools may work in ways not adequately defined by the category." (http://scholar.lib.vt.edu/theses/available/etd-12152009-131820/unrestricted/Pfeiffer_DV_T_2009.pdf)
"In general, there are currently two methods of digital fabrication:
1) Solid Free-Form Fabrication, Common methods of solid free-form fabrication are 3D Printing (3DP), Selective Laser Sintering (SLS), Stereo-lithography (SLA), Fused Deposition Modeling (FDM), and Laminated Object Manufacturing (LOM), among others.
2) and CNC (computer numerically controlled machining tools)." (http://scholar.lib.vt.edu/theses/available/etd-12152009-131820/unrestricted/Pfeiffer_DV_T_2009.pdf)