This lecture introduces the concepts of economic growth and development, focusing on GDP as a key measure of economic activity. The instructor explains how GDP is calculated, its significance in understanding economic growth at different levels, and its limitations as a measure of overall prosperity. The lecture also delves into the complexities of measuring development beyond economic indicators, highlighting the challenges in assessing quality of life. Additionally, the lecture covers the structure of national accounts, detailing the interactions between producers, consumers, and the public sector in an economy. The role of exports, imports, and monetary flows in the economic circuit is also discussed, emphasizing the importance of exchange rates in international trade.