Long time ago,there's no GPU for computer system. Game will use cpu to draw all graphics. Later,GPU come out,it has all functions with hardware chips,all need to be configured to make it work as excepted. In about 2002,GPU start to support shadering programming for vertex and pixel functions. That starts the programming pipeline.
Some description in Wikipedia:Fixed-function
An article about GPU Evolution:GPU Evolution
Currently,this is discarded for modern GPU.
