The document discusses international trade theory, defining globalization as the interconnectedness of economies and cultures driven by technology, trade liberalization, and multinational corporations. It examines various trade theories, including mercantilism, absolute advantage, comparative advantage, Heckscher-Ohlin theory, product life-cycle theory, new trade theory, global strategic rivalry theory, and Porter's diamond theory, which explain why countries and firms engage in trade and the factors influencing their competitive advantages. The relevance of these theories in today's economic environment is also analyzed, noting that while some older theories have become outdated, others like the Heckscher-Ohlin theorem and new trade theory remain applicable.