Who are "The Makers" in the novel, The Wild Robot?

The Makers are spoken of but never seen, and are highly influential human beings in the novel. The Makers own and operate the factory, where they design and produce the robots that become those like Roz and RECO 1. The Makers are very careful about their products and profits, and so send RECO robots to recover the robots lost at the bottom of the sea by the island, and later send three RECO robots to retrieve Roz from the island.