"World" can refer to the domain of discourse, but it can also mean several other things:
World is often synonymous with the planet Earth (especially when capitalised: the World).
The word "world" is sometimes used as a synonym for planet; for example, Mars and Jupiter are two worlds within the solar system.
It is sometimes used to refer to the entire Universe. This is less common now that knowledge of space is more commonplace; however, it is still used vaguely in this sense (as in "the whole wide world").
World can be used in less literal terms; for example, when describing two people with very little in common, one can describe them as "living in two different worlds." When a person refers to the "end of the world," that person usually means "the end of everything I am familiar with."
In another religious sense, in Christianity the world refers to the fallen and corrupt world order of human society outside the community of believers. The world is frequently cited alongside the flesh and the Devil as a source of temptation that Christians should flee.
World can also refer to a fictional setting, for example the world of Star Trek or the world of Lord of the Rings. See fictional realm.
First World, Second World, Third World
The terms First World, Second World, and Third World are used to divide the nations of Earth into three broad categories. Originally, First World referred to capitalist societies, Second World to centrally planned Communist ones, and Third World for the remainder of the planet, mostly developing countries based on tribal systems.
In the context of the the Cold War, "First World" refers to nations that were within the United States' sphere of influence - e.g., the NATO countries of North America and Western Europe, Japan, and some of the former British colonies such as Australia, New Zealand, and South Africa.
"Second world" refers to nations within the Soviet Union's sphere of influence, e.g. Warsaw Pact countries. Besides the Soviet Union proper, most of Eastern Europe was run by satellite governments working closely with Moscow. This term may or may not also refer to Communist countries whose leadership were at odds with Moscow, e.g. China and Yugoslavia.
"Third World" refers to nations within neither sphere of influence. After World War II, the First and Second Worlds struggled to expand their respective spheres of influence to the Third World. The militaries and intelligence services of the United States and the Soviet Union worked both secretly and overtly to influence Third World governments, with mixed success.
With the 1991 collapse of the Soviet Union and the fall of Leninist Communism, the term Second World largely fell out of use - though Third World remains popular. The remaining Communist countries either became more isolated from the world economy, as in North Korea and Cuba, or began integrating capitalist concepts such as private enterprise into their societies, and forging new trading ties with external capitalist economies, as in Vietnam and China.The terms First World, Second World, and Third World, along with the terms Fourth World and Fifth World, are still used today by independent scholars of secessionist movements or micronationalists, however.
The terms First World, Second World, and Third World can be best understood in Human Development Index (HDI) terms, where blue countries correspond roughly with the modern First World, yellow countries correspond roughly with the modern Second World, and red countries correspond roughly with the modern Third World. The Fourth and Fifth World, on the other hand, represent nations without fully-recognised states, and thus outside of the United Nations. The Fourth World is made up of medium- to large-sized nations without states, while the Fifth World is comprised of small nations with strong and established national identities.
- First World
- Second World
- Third World
- Fourth World
- Fifth World
- Least Developed Countries (Fourth World)
- Human Development Index