Androids are automatons made almost entirely of inorganic parts, save for one single portion. In the center of its chest chassis, there is a container containing a "Soul Core." This is extracted from a living being, often human and willingly donated as a means of living on after death, though the android often has no memory of their past selves. Occasionally an Android is said to "dream" of their past lives, but this is not confirmed.
The "Soul Core" is what distinguishes them from other, normal Robots. The Accord recognizes them as Citizens, though some societies see them simply as machines with advanced AI.