Meines Wissens ist es ein neuerer Begriff für das, was wir früher "Dritte Welt" und später "Entwicklungsländer" genannt haben. Die meisten davon sind grösstenteils auf der Südhalbkugel, aber sicherlich nicht alle, und nicht alle Länder auf der Südhalbkugel fallen in diesen Bereich.
Edit: Hier hat es übrigens einen interessanten Text zum Thema:
"OK, so the Global South/Global North are bad words, but what to use instead? There is no obvious substitute that is more descriptively accurate, less homogenizing and less suggestive of (geographic) determinism. But then don’t use any categorization that is so general and coarse. There is a good reason why there is no appropriate alternative term: the countries of the world are too diverse to fit into two boxes: one for South and one for North, one for developed and one for non-developed, one for powerful, and one for oppressed.
Be specific about what the term is referring to, and be concrete about the set of countries that is covered. If you mean the 20 poorest countries in the world, say the 20 poor countries in the world, not countries of the Global South. If you mean technologically underdeveloped countries, say that and not countries of the Third World. If you mean rich, former colonial powers from Western Europe, say that and not the Global North. It takes a few more words, but it is more accurate and less misleading.
It is a bit ironic that the Global South/Global North terms are most popular among scholars and activists who are extremely sensitive about the power of words to shape public discourses, homogenize diverse populations, and support narratives that take a life of their own, influencing politics and public policy. If that’s the case, it makes it even more imperative to avoid terms that are inaccurate, homogenizing and misleading on a global scale."