What is the G of G8?

People say "the G8 summit has held in Hokkaido, Japan". Now here is the question; What is the G of G8? I guess G is about Great 8 Countries in terms of influential power. If so, what kind of message do they express?

The stock market has not reacted by this summit so far. Many investors seem to care of the US economy and financial system as well as the impact of inflation including the sharp movement of oil prices. Why the gap between rich and poor happens all the time? I remember that Ethiopia faced with poverty in 1984-85 when the aid movement came into being among artists in the UK and US.

The answer might lay inside of our mind. Selfish, lack of kindness, careless...