This document provides an introduction to international economics. It distinguishes international economics from domestic economics and explains that international economics examines how nations interact through trade, money flows, investment, and immigration. It identifies seven main themes in international economics: (1) gains from trade, (2) patterns of trade, (3) how much to trade, (4) balance of payments, (5) exchange rate determination, (6) international policy coordination, and (7) international capital markets. It also distinguishes between the trade and monetary aspects of international economics.