
The BASIC countries are a bloc of four large newly industrialized countries – Brazil, South Africa, India and China – formed by an agreement on 28 November 2009. The four committed to act jointly at the Copenhagen climate summit, including a possible united walk-out if their common minimum position was not met by the developed nations.

BRIC is a grouping acronym referring to the countries of Brazil, Russia, India, and China deemed to be developing countries at a similar stage of newly advanced economic development, on their way to becoming developed countries. It is typically rendered as "the BRIC," "the BRIC countries," "the BRIC economies," or alternatively as the "Big Four". A related acronym, BRICS, adds South Africa.

BRICS is the acronym coined to associate five major emerging national economies: Brazil, Russia, India, China, and South Africa. The BRICS members are known for their significant influence on regional affairs. Since 2009, the BRICS nations have met annually at formal summits. Brazil hosted the most recent 11th BRICS summit on 13–14 November 2019.

The CIVETS are six favored emerging market countries – Colombia, Indonesia, Vietnam, Egypt, Turkey, and South Africa. These countries are favored for several reasons, such as "a diverse and dynamic economy" and "a young, growing population". This list is comparable to the Next Eleven, devised by Jim O'Neill of Goldman Sachs.

A developed country, industrialized country, more developed country (MDC), or more economically developed country (MEDC), is a sovereign state that has a developed economy and advanced technological infrastructure relative to other less industrialized nations. Most commonly, the criteria for evaluating the degree of economic development are gross domestic product (GDP), gross national product (GNP), the per capita income, level of industrialization, amount of widespread infrastructure and general standard of living. Which criteria are to be used and which countries can be classified as being developed are subjects of debate.

A developing country is a country with a less developed industrial base (industries) and a low Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreement on which countries fit this category. A nation's GDP per capita, compared with other nations, can also be a reference point. In general, the United Nations accepts any country's claim of itself being "developing".

Emerging and growth-leading economies (EAGLEs) are a grouping of key emerging markets developed by BBVA Research. The EAGLE economies are expected to lead global growth in the next 10 years, and to provide important opportunities for investors.

The concept of First World originated during the Cold War and comprised countries that were aligned with NATO and the United States, and opposed the Soviet Union and/or communism during the Cold War. Since the collapse of the Soviet Union in 1991, the definition has instead largely shifted to any country with little political risk and a well functioning democracy, rule of law, capitalist economy, economic stability, and high standard of living. Various ways in which modern First World countries are often determined include GDP, GNP, literacy rates, life expectancy, and the Human Development Index. In common usage, as per Merriam-Webster, "first world" now typically refers to "the highly developed industrialized nations often considered the westernized countries of the world".

The G20 is an international forum for the governments and central bank governors from 19 countries and the European Union (EU). Founded in 1999 with the aim to discuss policy pertaining to the promotion of international financial stability, the G20 has expanded its agenda since 2008 and heads of government or heads of state, as well as finance ministers, foreign ministers and think tanks, have periodically conferred at summits ever since. It seeks to address issues that go beyond the responsibilities of any one organization.

The G33 is a coalition of developing countries, established prior to the 2003 Cancun ministerial conference, that have coordinated during the Doha Round of World Trade Organization negotiations, specifically in regard to agriculture.

The Global South is an emerging term, used by the World Bank and other organizations, identifying countries with one side of the underlying global North–South divide, the other side being the countries of the Global North. As such the term does not inherently refer to a geographical south; for example, most of the Global South is actually within the Northern Hemisphere.

The Group of 15 (G-15) is an informal forum set up to foster cooperation and provide input for other international groups, such as the World Trade Organization (WTO) and the Group of Seven. It was established at the Ninth Non-Aligned Movement Summit Meeting in Belgrade, Yugoslavia, in September 1989, and is composed of countries from Latin America, Africa, and Asia with a common goal of enhanced growth and prosperity. The G-15 focuses on cooperation among developing countries in the areas of investment, trade, and technology. Membership has since expanded to 18 countries, but the name has remained unchanged. Chile, Iran and Kenya have since joined the Group of 15, whereas Yugoslavia is no longer part of the group; Peru, a founding member-state, decided to leave the G-15 in 2011.

The Group of 77 (G77) at the United Nations is a coalition of 134 developing countries, designed to promote its members' collective economic interests and create an enhanced joint negotiating capacity in the United Nations. There were 77 founding members of the organization headquartered in Geneva, but it has since expanded to 134 member countries according to the organization. China does not consider itself to be a member, nor did it when it was generally regarded as a developing country. However, the country supports and financially contributes to G77, and official statements are made with China. Guyana holds the chairmanship as of 2020.

The Group of Eight (G8) was an inter-governmental political forum from 1997 until 2014. It had formed from incorporating the country of Russia into the Group of Seven, or G7, and returned to its previous name after Russia was disinvited in 2014.

Group of Eleven (G11) is a forum, constituted by mostly developing countries aimed at easing their debt burden, narrowing the income gap with rich countries and lifting their people out of poverty.

The Group of Seven (G7) is an intergovernmental organization consisting of Canada, France, Germany, Italy, Japan, the United Kingdom and the United States. The heads of government of the member states, as well as the representatives of the European Union, meet at the annual G7 Summit.

The heavily indebted poor countries (HIPC) are a group of 39 developing countries with high levels of poverty and debt overhang which are eligible for special assistance from the International Monetary Fund (IMF) and the World Bank.

The term Latin America and the Caribbean (LAC) is an English-language acronym referring to the Caribbean and Latin America region. The term LAC covers an extensive region, extending from The Bahamas and Mexico to Argentina and Chile. The region consists over 670,230,000 people as of 2016, and spanned for 21,951,000 square kilometres (8,475,000 sq mi).

The least developed countries (LDCs) is a list of developing countries that, according to the United Nations, exhibit the lowest indicators of socioeconomic development, with the lowest Human Development Index ratings of all countries in the world. The concept of LDCs originated in the late 1960s and the first group of LDCs was listed by the UN in its resolution 2768 (XXVI) of 18 November 1971.

MENA is an English-language acronym referring to the Middle East, North Africa and the Horn of Africa, which corresponds to the Greater Middle East or the Arab World. It is alternatively called the WANA, as well as the MENAP, which also includes Central Asia and the South Asian country of Pakistan. The MENAP covers an extensive region stretching from the Maghreb in the west to Pakistan and Afhanistan in the east. The MENA acronym is often used in academia, military planning, disaster relief, media planning as a broadcast region, and business writing. Moreover, the region shares a number of cultural, economic and environmental similarities across the countries; for example, some of the most extreme impacts of climate change will be felt in the region.

MINT is an acronym referring to the economies of Mexico, Indonesia, Nigeria, and Turkey. The term was originally coined in 2014 by Fidelity Investments, a Boston-based asset management firm, and was popularized by Jim O'Neill of Goldman Sachs, who had created the term BRIC. The term is primarily used in the economic and financial spheres as well as in academia. Its usage has grown specially in the investment sector, where it is used to refer to the bonds issued by these governments. These four countries are also part of the "Next Eleven".

The category of newly industrialized country (NIC), newly industrialized economy (NIE) or middle income country is a socioeconomic classification applied to several countries around the world by political scientists and economists. They represent a subset of developing countries whose economic growth is much higher than other developing countries; and where the social consequences of industrialization, such as urbanization, are reorganizing society.

The North–South divide is a socio-economic and political division of Earth popularized in the late 20th century and early 21st century. Generally, definitions of the Global North is not exclusively a geographical term, and it includes Australia, Canada, most Western European countries, Israel, Japan, New Zealand, Singapore, South Korea, Taiwan (ROC) and the United States. The Global South is made up of Africa, Latin America and the Caribbean, Pacific Islands, and the developing countries in Asia, including the Middle East. It is home to: Brazil, India and China, which, along with Indonesia and Mexico, are the largest Southern states in terms of land area and population.

PIGS is an acronym used in economics and finance. The PIGS acronym originally refers, often derogatorily, to the economies of the Southern European countries of Portugal, Italy, Greece, and Spain. During the European debt crisis, the variant PIIGS, or GIPSI, was also increasingly used to refer to the economies of Portugal, Ireland, Italy, Greece, and Spain, EU member states that were unable to refinance their government debt or to bail out over-indebted banks on their own during the crisis.

The International Solar Alliance (ISA) is an alliance of 121 countries initiated by India, most of them being sunshine countries, which lie either completely or partly between the Tropic of Cancer and the Tropic of Capricorn. The primary objective of the alliance is to work for efficient consumption of solar energy to reduce dependence on fossil fuels. This initiative was first proposed by Indian Prime Minister Narendra Modi in a speech in November 2015 at Wembley Stadium(London HA9 0WS, United Kingdom), in which he referred to sunshine countries as Suryaputra. The alliance is a treaty-based inter-governmental organization. Countries that do not fall within the Tropics can join the alliance and enjoy all benefits as other members, with the exception of voting rights. After the United Nations, it is the largest grouping of states world-wide.

The Second World is a term used during the Cold War for the industrial socialist states that were under the influence of the Soviet Union. In the first two decades following World War II, 19 communist states emerged; all of these were at least originally within the Soviet sphere of influence, though some broke with Moscow and developed their own path of socialism while retaining Communist governments. But most communist states remained part of this bloc until the fall of the Soviet Union in 1991; afterwards, only five Communist states remained: China, North Korea, Cuba, Laos, and Vietnam. Along with "First World" and "Third World", the term was used to divide the states of Earth into three broad categories.

The term "Third World" arose during the Cold War to define countries that remained non-aligned with either NATO or the Warsaw Pact. The United States, Canada, Japan, South Korea, Western European nations and their allies represented the First World, while the Soviet Union, China, Cuba, and their allies represented the Second World. This terminology provided a way of broadly categorizing the nations of the Earth into three groups based on political and economic divisions. Since the fall of the Soviet Union and the end of the Cold War, the term Third World has decreased in use. It is being replaced with terms such as developing countries, least developed countries or the Global South. The concept itself has become outdated as it no longer represents the current political or economic state of the world.

VISTA is an acronym for Vietnam, Indonesia, South Africa, Turkey, Argentina.

A high-income economy is defined by the World Bank as a country with a gross national income per capita of US$12,536 or more in 2019, calculated using the Atlas method. While the term "high-income" is often used interchangeably with "First World" and "developed country", the technical definitions of these terms differ. The term "first world" commonly refers to countries that aligned themselves with the U.S. and NATO during the Cold War. Several institutions, such as the Central Intelligence Agency (CIA) or International Monetary Fund (IMF), take factors other than high per capita income into account when classifying countries as "developed" or "advanced economies". According to the United Nations, for example, some high-income countries may also be developing countries. The GCC countries, for example, are classified as developing high-income countries. Thus, a high-income country may be classified as either developed or developing. Although the Vatican City is a sovereign state, it is not classified by the World Bank under this definition.