If you are interested in the world of numerical control and CNC machines, you surely must have heard about the word G-code. For those of you who are not familiar with this term let me assure you that this is not rocket science of some thing of a classified nature. Basically G-code is used to refer to various types of code which is used to program and control the motion of CNC machines. Originally it referred to the code developed by the Electronics Industry Alliance as early as 1960. But of late although the name is still in popular use, currently it does not refer to a particular or specific language but there are different variation of the this code with each specific to some vendor or manufacturer.
This is so because there is very little interoperability due to the vast nature of machine tool configurations which are available currently. An attempt was made to standardise this code when in the year 1980 a language was named by the name of RS274D which was a sort of final revision of the G-code.
It also refers to various commands which are given as a part of the programming language meant to control the movements of the machine tool which are controlled by motors who get their signals from computers. To give a few examples of such G-codes just look at the following.
G00 -- Rapid Positioning G01 -- Linear Interpolation