This document provides an overview of key concepts in economics. It discusses how economics involves studying decision-making in the context of scarcity. It also distinguishes between microeconomics, which focuses on individual agents, and macroeconomics, which focuses on broad issues like growth and unemployment. The document outlines different economic systems including traditional, command, and market economies. It notes that most modern economies are mixed systems that combine elements of each. Key terms like fiscal and monetary policy, economic theories and models, and globalization are also defined.