This document discusses various topics related to trade and economics. It defines trade as the buying, selling and exchange of goods and services. It defines aids to trade as activities that facilitate trade, such as banking, transportation, insurance, warehousing, packaging and advertising. It also classifies trade into internal/home trade within a country and international/external trade between countries. The document defines economics as the study of human activities related to allocating scarce resources to produce goods and services. It discusses different economic systems including capitalist, socialist and mixed systems.