The world is divided into developed and developing countries based on economic, social, and cultural criteria.
Developed countries are characterized by high income levels, advanced industries, scientific and technological progress, as well as high standards of education and healthcare.
Developing countries, on the other hand, often face low income, weak industries, poverty, unemployment, and limited educational and health services.

The main classification criteria include:
1- Economic criteria such as per capita income and industrial development.
2- Social criteria such as education, healthcare, and life expectancy.
3- Cultural criteria such as scientific research and intellectual development.

In conclusion, the higher the level of economic, social, and cultural development, the closer a country is considered to being a developed country.