G20 vs G8
G20 and G8 are abbreviations for forums of industrialized and developed countries of the world. G8 is older, coming into existence at the behest of France in 1975. It brought together France, Germany, Italy, Japan, UK and the US (G6). It was then G6, but with Canada joining in 1976, the coalition became G7. Russia joined the group in 1997 making it G8 and since then the coalition is called G8 only. Surprisingly, European Union is considered to be a part of G8 but it cannot host or chair any of the summits organized by G8. Ministers of the member nations meet regularly and discuss matters of mutual interest.
G20 on the other hand is an informal group consisting of 19 nations and the European Union, thereby bringing the number to 20. It also consists of representatives of International Monetary Fund (IMF) and the World Bank. This group came into existence at the suggestion of G7 in 1997 (till then the group was G7 as Russia joined in 1999 to make it G8) to look for solutions to world financial crisis. Since then, every fall, finance ministers of these countries have been holding discussions on issues of global importance. G20 exerts considerable economic clout globally with these economies making up 85% of the gross national product of the world and 80% of the world trade. Amidst global financial crisis, the then US President in 2008 suggested that G20 play a greater role in resolving the crisis. Since then, the group has grown in stature and annual summits began to take place. These summits are attended by finance ministers and central bank governors of all the member countries.
Both G8 and G20 are similar in the sense that there is no permanent organizational nature with Presidency revolving among the members. Since the emergence of G20, it has taken over G8 as far as financial matters are concerned but G8 still holds clout as these industrialized nations also discuss other matters such as health, education, trade, energy, pollution etc.
G8 is the spear head of the most industrialized nations of the world with the group holding considerable clout discussing matters of international importance in its summit.
G20 is a forum or informal group of G8 plus 12 other nations that hold summits to discuss international financial condition and to suggest ways to remove roadblocks.