The development of a country is measured with statistical indexes such as income per capita (per person) (gross domestic product), life expectancy, the rate of literacy, et cetera. The UN has developed the Human Development Index (HDI), a compound indicator of the above statistics, to gauge the level of human development for countries where data is available.
Developing countries are, in general, countries that have not achieved a significant degree of industrialization relative to their populations, and have, in most cases, a medium to low standard of living. There is a strong correlation between low income and high population growth.
The terms utilized when discussing developing countries refer to the intent and to the constructs of those who utilize these terms. Other terms sometimes used are less developed countries (LDCs), least economically developed countries (LEDCs), "underdeveloped nations" or Third World nations, and "non-industrialized nations". Conversely, developed countries, most economically developed countries (MEDCs), First World nations and "industrialized nations" are the opposite end of the spectrum.
To moderate the euphemistic aspect of the word developing, international organizations have started to use the term less economically developed country (LEDCs) for the poorest nations—which can, in no sense, be regarded as developing. That is, LEDCs are the poorest subset of LDCs. This may moderate against a belief that the standard of living across the entire developing world is the same.
The concept of the developing nation is found, under one term or another, in numerous theoretical systems having diverse orientations — for example, theories of decolonization, liberation theology, Marxism, anti-imperialism, and political economy. Another important indicator is the sectoral changes that have occurred since the stage of development of the country. On an average, countries with a 50% contribution from the Secondary sector of Manufacturing have grown substantially. Similarly countries with a tertiary Sector stronghold also see greater rate of Economic Development.
The "BRIC" countries, Brazil, Russia, India, and China are difficult to categorize because of their rapid economic development in recent years. However, they are still not developed countries.
There is criticism of the use of the term 'developing country'. The term implies inferiority of a 'developing country' or 'undeveloped country' compared to a developed country, which many countries dislike.
It assumes a desire to 'develop' along the traditional 'Western' model of economic development, which a few countries, such as Cuba and Bhutan, choose not to follow.
The term 'developing' implies mobility and does not acknowledge that development may be in decline or static in some countries, particularly in southern African states worst affected by HIV/AIDS. In such cases, the term developing country may be considered a euphemism. The term implies homogeneity between such countries, which vary widely. The term also implies homogeneity within such countries when wealth (and health) of the most and least affluent groups varies widely. Similarly, the term 'developed country' incorrectly implies a lack of continuing economic development/growth in more-developed countries.
In general, development entails a modern infrastructure (both physical and institutional), and a move away from low value added sectors such as agriculture and natural resource extraction. Developed countries, in comparison, usually have economic systems based on continuous, self-sustaining economic growth in the tertiary sector of the economy and quaternary sector of the economy and high material standards of living. However, there are notable exceptions, as some countries considered developed have a significant component of primary industries in their national economies, e.g., Norway, Canada, Australia. The USA and Western Europe have a very important agricultural sector, and are major players in international agricultural markets. Also, natural resource extraction can be a very profitable industry (high value added), e.g., oil extraction.
An alternative measurement that has been suggested is that of Gross national happiness, measuring the actual satisfaction of people as opposed to how money-oriented a country is.