I want to know it the term graphics pipeline, is referring to an actual hardware implementation of a pipeline for graphics processing or if it is referring to a sofware methodology.
The term graphics pipeline refers generally to the method of rasterization rendering that is supported by the graphics hardware. If graphics hardware has no support for 3D the pipeline is emulated in a software graphics pipeline. An example is e.g. Mesa which was
used on Linux when no ATI or NVIDIA driver were available to do 3D. But since all major OS' have decent drivers for 3d (OpenGL) there is no need for a software graphics pipeline.