A fundamental concept in finance is the classification of countries into developed and developing categories. Developing countries are those that have not yet reached the level of economic and social advancement as developed nations. This classification is based on factors such as per capita income, industrialization, and human development indices. However, it is important to note that this classification is not static and countries can transition from one category to another based on their economic growth and development. This understanding of developing countries is crucial in making informed financial decisions and analyzing global markets.