I am a bit a newbie, so here's my question. How does this post processor work? Where do i have to put it?
In the context of how a the g code is interpreted by the machine controller software each machine is a little bit different from the next, one model from another, one manufacturer from another. Cam packages produce the g code and then customize (postprocess) the code to suit the machine which will be used to make the part. The postprocessor is simply the part of the program which modifies the roar code. Sometimes the postprocessing is simple like removing the header and footer from the code, other times (particularly on complex multi axis machines) it is a lot more involved. Sometimes the software vendor can provide the postprocessor with the initial purchase of the software, sometimes the postprocessor has to be created from scratch.