Third World is a term first coined in 1952 by French demographer Alfred Sauvy to distinguish nations that aligned themselves with neither the West nor with the Soviet Bloc during the Cold War. Today, however, the term is frequently used to denote nations with a low UN Human Development Index (HDI), independent of their political status (meaning that the PRC, Russia and Mexico, all of which were very strongly aligned during the Cold War, are often termed third world). However, there is no objective definition of Third World or "Third World country" and the use of the term remains controversial. In geographical and political academia, it is almost never used, as it is seen as being out of date, colonialist, othering and inaccurate. In general, Third World countries are not as industrialized or technologically advanced as OECD countries, and therefore in academia, the more politically correct term to use is "developing nation".
Terms such as Global South, less wealthy nations, developing countries, least developed countries and the Majority World have become more popular in many circles, due to the derogatory and out of date connotations of describing a 'Third' world. Development workers also call them the two-thirds world (because two-thirds of the world is underdeveloped) and The South. The term Third World is also disliked as it may imply the false notion that those countries are not a part of the global economic system. Some note that the underdevelopment of Africa, Asia and South America during the Cold War was influenced, or even caused by the Cold War economic, political, and military maneuverings of the most powerful nations of the time. (See Emerging Markets)
The term Fourth World is used by some writers to describe the poorest Third World countries, those which lack industrial infrastructure and the means to build it. More commonly, however, the term is used to describe indigenous peoples or other oppressed minority groups within First World countries. ..... source - wikipedia
