International trade refers to the exchange of goods, services, technology, capital, and intellectual property across national boundaries. The theories of international trade have evolved over time from classical approaches emphasizing production efficiency to contemporary approaches recognizing technology, innovation, imperfect competition, and government intervention. These theories help explain why nations engage in trade, how trade patterns develop, and the factors that influence international competitiveness. The classical conceptions of international trade primarily focus on differences in production costs and resource availability. They assume perfect competition, full employment, and free trade among nations. Adam Smith's Theory of Absolute Advantage states that a country should specialize in producing goods that it can manufacture more efficiently than other countries. According to Smith, international trade benefits all participating countries because each nation specializes in products where it has absolute efficiency and imports goods produced more efficiently elsewhere. This specialization increases productivity, reduces costs, and expands consumer choice. David Ricardo's Theory of Comparative Advantage extended Smith's ideas by arguing that even if one country has an absolute advantage in producing all goods, trade can still be beneficial. A country should specialize in producing goods for which it has the lowest opportunity cost and import goods with relatively higher opportunity costs. Comparative advantage remains one of the most influential principles in international trade because it demonstrates that specialization based on relative efficiency increases global welfare. The Heckscher-Ohlin Theory explains trade based on differences in factor endowments. According to this theory, countries export goods that intensively use their abundant and relatively inexpensive factors of production, such as labour, capital, or land, and import goods requiring scarce factors. Labour-rich countries tend to export labour-intensive goods, while capital-rich countries export capital-intensive products. The Factor Price Equalization Theory suggests that free trade tends to equalize wages and returns to capital across countries by increasing demand for abundant production factors. Although complete equalization rarely occurs