This document provides an overview of the key concepts that will be covered in a module on theory and the European Union. It introduces the notion of the state and how that relates to the history and development of the EU. It then discusses characteristics of states, interstate cooperation through international organizations and regional integration associations. Theories of European integration are presented, including functionalism, neofunctionalism and spillover. The document notes that the EU now sits between an international organization and a state, with aspects of both federalism and confederalism. It concludes with an assignment asking students to identify pros and cons of the EU based on their reading.