What are the three blocs of nations formed after the war?

The three blocs refer to First World, Second World and Third World terms. They arose out of the United Nations. Mostly it is a sociological term. Or a political term. The term Fourth World has been developed since WWII. The explanation below comes from an organization called Nations Online developed to improve global awareness. It is the best explanation I have ever seen on this subject. Thankfully the Second World has shrunk due to the end to many communist countries becoming independent countries.

Four Worlds

After World War II the world split into two large geopolitical blocs and spheres of influence with contrary views on government and the politically correct society:

1 - The bloc of democratic-industrial countries within the American influence sphere, the "First World".

2 - The Eastern bloc of the communist-socialist states, the "Second World".

3 - The remaining three-quarters of the world's population, states not aligned with either bloc were regarded as the "Third World."

4 - The term "Fourth World", coined in the early 1970s by Shuswap Chief George Manuel, refers to widely unknown nations (cultural entities) of indigenous peoples, "First Nations" living within or across national state boundaries.

__ Definitions

The term "First World" refers to so called developed, capitalist, industrial countries, roughly, a bloc of countries aligned with the United States after World War II, with more or less common political and economic interests: North America, Western Europe, Japan and Australia.

Countries of the "First World"

"Second World" refers to the former communist-socialist, industrial states, (formerly the Eastern bloc, the territory and sphere of influence of the Union of Soviet Socialists Republic) today: Russia, Eastern Europe (e.g., Poland) and some of the Turk States (e.g., Kazakhstan) as well as China.

Countries of the "Second World"

"Third World" are all the other countries, today often used to roughly describe the developing countries of Africa, Asia and Latin America.

The term Third World includes as well capitalist (e.g., Venezuela) and communist (e.g., North Korea) countries, as very rich (e.g., Saudi Arabia) and very poor (e.g., Mali) countries.

Below

Countries of the "Third World"

Third World Countries classified by various indices: their Political Rights and Civil Liberties, the Gross National Income (GNI) and Poverty of countries, the Human Development of countries, and the Freedom of Information within a country.

The term "Fourth World" first came into use in 1974 with the publication of Shuswap Chief George Manuel's: The fourth world : an Indian reality (Amazon link to the book), the term refers to nations (cultural entities, ethnic groups) of indigenous peoples living within or across state boundaries (nation states).

see Native American Indians

American Indian Nations.