Orphan Black is a sci-fi conspiracy show, and as such, it's filled with secret plots, secret counter-plots, subterfuge, and improbable twisting revelations. But the most improbably twisting revelation of them all is that everything you know about the clones played by Tatiana Maslany is false. Sarah, Allison, Helena, Cosima—they're not really clones at all. They're robots.
Fear not; this isn't some sort of diabolical spoiler that will ruin your enjoyment of the third season. The fact that the clones are robots is simply a genre observation. Ever since robots as a concept were invented, they've been analogous to clones, and vice versa. Robots prompt people to question whether this thing that looks like them is a physical object, or whether it’s in fact a person. And since robots in science fiction are so often workers, the question of their humanity has from the start also been a question about class—about how people treat those workers, or robots, or the clones of Orphan Black, laboring on their behalf.
The term “robot” entered modern usage when it was coined by the Czech writer Karel Capek in the 1920 play R.U.R. The story imagined its artificial servants not as metal men of nuts and bolts, but as biological products, much like clones. Domin, the robot-factory manager in the play, cheerfully gives a tour pointing out "the spinning mill for nerves. The spinning mill for veins. The spinning mill where miles and miles of digestive tract are made at once." These first robots were fleshy, goopy beings that grew like biological critters. In the play, robots are basically human bodies borne of mechanical production and process. Looking back, Domin's creations are more akin to Orphan Black's protagonists than they are R2D2.