This article explains international trade theory and policies in simple terms. It discusses why countries trade, detailed trade models, economic effects of tariffs and non-tariff barriers, and the political and developmental aspects of trade. The researchers look at neoclassical trade theory and extend it with empirical tests, technology-based theories, and effects of economies of scale and imperfect competition. They also explore factors like trade in services, international factor movements, and the impact of exchange rate movements on trade. The findings provide insights into how trade policies influence economies and development, showcasing the complexities and dynamics of international trade relationships.