Decentralization is what happens when a government, a company, or a large group stops keeping all the power and all the work in one central place — the capital, the head office, the one room at the top — and moves those parts out to several smaller places. Towns, branches, or local teams then get to decide more for themselves. It is a formal word; in ordinary talk people say “give local people more say” or “spread the power out.” The opposite is centralization, which pulls everything back into one place. In recent years people also stretch the word to computers and money: they mean a system with no single company or bank sitting in the middle. That is the same idea, not a new one. British spelling often writes decentralisation, with an s; it is the same word.