Third World - Why the confusion?
There's a lot of confusion about the term "Third World", and for good reason: it's out of date. It's roots are in the Cold War. The terms were coined in the 1950's by someone prominent in foreign affairs, maybe Dag Hammarksjold or Dean Acheson, I can't remember exactly. The "First World" refered to the Western Democracies and the "Second World" to Communist countries. The "Third World" encompassed the mass of non-aligned nations. Because the majority of non-aligned countries were "under-developed", "Third World" became synonymous with that term.
The World Bank uses more precise terminology: "Developed", "Developing", and "Less Developed. " The confusion is the result of different people using "Third World" to signify either "Developing", "Less Developed", or both. It's impossible to say who is right.
P.S. I'm sure that the World Bank classifies Venezuela as "Developing", but having lived here for a number of years "Regressing" would be more appropriate.
Origin of the term "Third World"
From word origins dot org:
This political term is originally French. Tiers Monde was coined in 1955 by French demographer Alfred Sauvy and first used in print the following year by G. Balandier. The English is a literal translation, or calque, of the French.
Sauvy used the archaic tiers instead of the modern troisième as a parallel construction to the Tiers État, or Third Estate. The term quickly entered English soon after its coining.
The First World is the industrialized West, the Second World are the Communist nations of the Soviet Union and Eastern Europe, and the Third World are all the rest.
(Source: Oxford English Dictionary, 2nd Edition)