The G8 is commonly referred to as a group of the world's "most industrialized" economies, with a membership that includes Canada, the United States, the United Kingdom, France, Germany, Italy, Japan and Russia.

You'll notice that the burgeoning economies of China and India are left out of this cozy group, as is any country from Africa or South America — one of the many reasons why the bigger G20 has eclipsed the G8 in importance and relevance in the last few years.

In fact, the G20 has now officially become the main international forum where global economic issues are addressed.

But the G8 remains a key forum for many other political and social issues, including global security, climate change, international development, health, crime and arms control.

Senior ministers and officials of G8 countries meet several times a year. Last year, Canada (as host of the 2010 summit) held a series of pre-G8 gatherings — including a meeting of foreign ministers in March in Gatineau, Que., an April meeting of G8 development ministers and senior officials in Halifax, and a pre-summit gathering of finance ministers and central bank governors in Iqaluit in February.

The G8 leaders themselves gather once a year. The 2011 edition of the summit is taking place in Deauville, France, on May 26 and 27.

5 summits in Canada

The 2010 summit in Huntsville, Ont., was the fifth hosted by Canada, after Ottawa-Montebello in 1981, Toronto in 1988, Halifax in 1995 and Kananaskis, Alta., in 2002.

G8 leaders from left, Prime Minister Stephen Harper, Russian President Dmitry Medvedev, European Commission President Jose Manuel Barroso, British Prime Minister David Cameron, French President Nicolas Sarkozy, U.S. President Barack Obama, German Chancellor Angela Merkel and Japanese Prime Minister Naoto Kan walk together after a lunch meeting at the G8 summit in Deauville, France, on May 26, 2011. Remy de la Mauveniere/Associated Press

The responsibility of hosting the G8 summit rotates annually in the following order: France, the United States, the U.K., Russia, Germany, Japan, Italy, and Canada. The 2011 summit in France marks the sixth time that country has played host.

The first summit (involving six nations) took place in France in 1975 at the invitation of then French President Valéry Giscard D'Estaing.

Back then, the agenda's focus was on one issue — how to deal with the oil crisis that was playing havoc with the world's biggest economies. Canada joined this exclusive club the following year at the summit in Puerto Rico.

The year after that — in 1977 — the European Community (now called the European Union) was invited to sit in as an observer. The EU now enjoys the privileges of G8 membership, but cannot host or chair a summit.

In 1998, Russia joined the G7, making it the G8.

The issues

Over the decades, the G6, G7 and G8 have tackled a broad range of social, economic and political issues. Past summit agendas have included attempts to increase aid to Africa, establishing a global fund to fight HIV/AIDS, debt relief for poor countries and curbing the spread of infectious diseases.

In Deauville, Canadian Prime Minister Stephen Harper and U.S. President Barack Obama will reportedly discuss the next stage of the North American perimeter security agreement.

Uprisings in the Middle East and North Africa are also expected to feature prominently in the group discussions at the summit. The deteriorating security situation in Syria and the NATO-led military mission in Libya will also spark debate.

Prime Minister Stephen Harper, European Commission President Jose Manuel Barroso and United States President Barack Obama take part in adding a few painting strokes to a copy of painting from the Group of Seven at the G8 summit in Huntsville, Ont., on June 25, 2010. Fred Chartrand/Canadian Press

The plight of G8 member Japan will also be discussed.

As with the G20, there are no formal votes taken at G8 summits. Summits end with the release of a communiqué, summarizing broad general areas of agreement and pointing to future goals the G8 leaders want to pursue.

The future

Whether it's considered a vital forum to exchange ideas or little more than a costly photo op (or a bit of both), the G8 process now attracts more questions about its relevance.

How can a group that represents less than half the world's economy and less than a quarter of its population adequately speak about something like global warming? That's one reason why host leaders routinely invite other non-member nations to join them.