A processor is the computing part: circuits and wire on a board, made in a Fabricator. Processors go into nav computers and control units, and through those into uplinks, forward HQs and haulers. A Lab, a research station, a sensor array and the lattice scanner are built with processors too, and each data core holds one.
Most of a processor's material cost is copper, through its circuits and wire. Copper is scarce in the Relay and common from the Static outward.