This document defines key concepts related to government and political systems. It begins by defining what a government is and its main components: people, power, and policy. It then discusses the definition of a state and the key elements that make a state: a population, territory, sovereignty, and a government. It also covers different types of governments like unitary, federal, and confederate systems. The document contrasts presidential and parliamentary forms of government. It concludes by discussing principles of government like popular sovereignty, separation of powers, and checks and balances.