BRICS refers to Brazil, Russia, India, China, and South Africa. It started as BRIC, a term coined by an economist and used by Goldman Sachs over twenty years ago to refer to countries that would become the economic powers of the future. Later, South Africa was included, and other terms were coined to refer to various configurations, like CIVETS (Colombia, Indonesia, Vietnam, etc.), EAGLES (Emerging and Growing-Leading Economies), MINT (Mexico, Indonesia, Nigeria, Turkey), and Next Eleven (Bangladesh, the Philippines, Indonesia, Iran, Pakistan, etc.). They are mostly part of the Global South, which is all countries except those in North America, Europe, and Israel, Japan, South Korea, Australia, and New Zealand.
The Global South, which includes Ukraine, is growing considerably and will soon take over the global economy because it has large numbers of young people who are eager workers and consumers:
https://www.bbc.com/news/business-22956470
A recent example is VIP, or Vietnam, Indonesia, and the Philippines, which have some of the highest economic growth rates and will eventually become among the premier investment sites even for the aging populations of the Global North.
The main leader is China, which has been experiencing unprecedented growth, i.e., an average growth rate of 7 pct per annum for more than 40 years, and within two decades lifted over 800 million of its people out of poverty. The main tactics employed by these countries is the East Asian Miracle, which was started by Japan and consists of combinations of coordination between public and private sectors, export orientation, heavy infrastructure development needed for manufacturing, mechanized agriculture, and mining, and essentially authoritarian forms of government, and is based on, interestingly enough, nineteenth-century Prussian state policies and three centuries of European mercantilism.
BRICS has lately become an organization and now includes Saudi Arabia, which has been trading with Russia and China without using the dollar.
The result is a growing multipolar global economy, with lots of bilateral trade and economic blocs outside the influence of the U.S. dollar, G-7, and even the IMF and WB. Many of them grew faster because they refused to give in to policies like IMF-WB structural adjustment, which would have forced them to open up their markets to exploitation by the West.
This increasing prosperity by most countries is a major threat to the U.S., which relies heavily on the use of the dollar as a global reserve currency (which is why, for example, it made deals with Saudi Arabia and OPEC to price oil in dollars and to invest profits in Wall Street in exchange for military support). The only way for that reserve currency to be maintained is for most of these countries to be economically weak and thus rely on the U.S. for help.