What is G20 organisation?

The G-20 (more formally, the Group of Twenty Finance Ministers and Central Bank Governors) is a group of finance ministers and central bank governors from 20 economies: 19 of the world's largest national economies, plus the European Union (EU). It also met twice at heads-of-government level, in November 2008 and again in April 2009. Collectively, the G-20 economies comprise 85% of global gross national product, 80% of world trade and two-thirds of the world's population.
The G-20 is a forum for cooperation and consultation on matters pertaining to the international financial system. It studies, reviews, and promotes discussion among key industrial and emerging market countries of policy issues pertaining to the promotion of international financial stability.