This chapter discusses the pedagogic device as the central theoretical resource used in the analyses in the book. The pedagogic device is a relational set of principles to describe the process of how any knowledge, disciplinary, community, local is transformed into educational knowledge, and communicated in pedagogy. In introducing the device, Bernstein is centrally concerned with how in the very structuring of pedagogy, from producing knowledge, to making selections around what to teach, to the actual teaching and learning processes, there are processes of differentiation, where who gets access to what educational knowledge, and how, is unevenly distributed across groups in society. Recontextualization takes place within a recontextualizing field that has two distinct arenas. The Official Recontextualizing Field (ORF), consisting of bureaucrats and specialized departments and sub-agencies of the state; and the Pedagogic Recontextualizing Field (PRF) which includes all interested educational actors (other than officials) with an interest in the circulation and reproduction of educational knowledge.