G-code (also known as RS-274) is the name of the most prevalent programming language for computer numerical control (CNC) in computer-aided design and manufacturing (CAD/CAM).
G-code provides metric-based numeric control of CAM-controlled equipment such as CNC milling machines. The fine-grained control enabled by G-code and other CNC languages afford the precision for additive and reduction-based fabricating using many materials.
The code used in G-code and other CNC code tells the computer that controls the motors of the manufacturing equipment how far to move and at what speed. A mill has a spinning tip that carves a metal block, for example, into an intricately machined part. G-code can provide the instructions to the computer-controlled equipment to move the head through 3D maneuvers at differing speeds to create a camshaft, which, as an example, may be used to control valve timing in a gasoline-powered engine.
The first numerical computer control language was developed by MIT in the late 1950s. The earliest version of G-Code was standardized by the Electronic Industries Alliance in the early 1960s. Today, the exact, reproducible manufacturing afforded by G-code and similar languages is used in the creation of all kinds of military and scientific equipment and consumer goods.