How do economic activity, ethics and cooperation fit together? This book introduces commercial society through the workings of markets and the rules and institutions that make exchange and trust possible. It explores value, cost, the division of labour and prices, alongside property, externalities, competition, financial institutions and public policy. It also considers practical topics such as saving, borrowing, investing and running a business, before turning to innovation and entrepreneurship. By connecting economic principles with everyday decisions, the book invites readers to consider commerce as a social activity with ethical questions and shared responsibilities.