What is a biodroid in Ghost in the Shell? In the episode 24 of GITS SAC 2nd GIG it becomes apparent that the member of Section 9, usually referred to as Proto, is actually not a human, but a "biodroid" prototype. What exactly is it and how different it is from cyberized people and androids?
As the name suggests, a bioroid is an android, but built with human body parts-- except that they don't have a human brain. 

The Major is a cyberized human, and an android is the least human of the three.