An interesting post noted that the term Third World country was actually a leftover from the Cold War. I’m not all that familiar with war terms, but this surprised me.
During the Cold War, the world was simplistically divided into three parts. The First World was made up of NATO allies (the capitalist Western bloc), the Second World comprised the countries aligned with the communist Soviet Eastern bloc, and the Third World was essentially made up of all the rest. The Third World, or unaligned countries at the time, were generally developing countries, although Ireland, Sweden and Switzerland were notable exceptions. They remained neutral during the war, but weren’t considered undeveloped.
Here’s a general picture:
These days, the Third World tends to refer strictly to developing countries, no matter what their political leanings. The First World now refers to highly developed countries with large incomes. Both terms are difficult to define, and I wonder how useful they really are. The term Fourth World has also arisen, to describe nomadic or nationless states or groups who are politically powerless.
Note: There is also the theory floating around that the Third World (speaking of Africa, mostly) came about following the terms Old World (Europe), and New World (the Americas). These were terms used to match the order in which European explorers discovered the world. It’s not an accurate origin, but it’s still somewhat logical, and probably less politically charged!