What do you mean by third world countries?
Third world countries are those nations that are considered underdeveloped or developing nations. These countries have seen the smallest amount of economic progress. These are countries which are associated with poverty. Most countries in Asia and some in Europe as well as Latin America fall into this category.
The third world countries are usually associated with high infant mortality rates, very little economic development, increased poverty rates and more. In third world countries, the natural resources are underdeveloped and they depend on nations that are industrialized to help them. These countries also have governments that are not stable and they usually are steeped in illiteracy and widespread disease. These countries also are steeped in foreign debt and lack a middle class.
On the other hand those countries that are industrialized and usually are democratic nations are considered first world countries. These nations have stable governments and are associated with high standards of living for their people. These nations are economically viable as well. Some of these first world countries are Canada and the United States as well as most of Western Europe.
The second world countries are those that are on the way to being first world countries but are not just there yet. They are lesser developed than the first world nations but they are more developed than the third world countries. These are like China and Eastern Europe.
In addition to third world countries, there is a new concept which is now gaining momentum called fourth world which describes those indigenous people who are living on the margins of society after they have been displaced by the settlers. These are people who are the native American tribes in the United States as well as the aboriginals in Australia. These people are considered the bottommost when it comes to economic strata. They are the poorest in the world.