As of the latest data, the three countries with the highest Human Development Index (HDI) rankings are Norway, Switzerland, and Ireland. The HDI ranks countries based on factors like life expectancy, education, and income.

It affects HDI because the HDI is made up of Living standard, life expectancy, and literacy rates. So if the countries are poor they won't have all the basic needs to life a sustainable life style and won't make there kids go to school and also with bad living standard comes lower average of life expectancy. So when these gets affected by poverty the HDI ranking goes completely down.

who

HDI is Human Development Index which is a Development Indicator which helps rank countries and makes it easier for someone to profile an LEDC or an MEDC

International inequality is the wide gap between rich countries and poor countries and how that gap is constantly increasing.

Intranational inequality on the other hand is the gap between the rich and the poor within the less developed countries.