Okay, so let's talk about G8. G8 is short for Group of Eight. Imagine you have eight friends who really like to play together. Sometimes you call them by their group name like "The Super Eight" or "The Octo-Buddies". That's kinda how countries work too.
G8 is a group of eight countries that work together to talk about important stuff like the economy, politics, and the environment. It's like a big meeting with people from all over the world who come up with ideas to make things better for everyone.
The members of the G8 are the United States, Canada, United Kingdom, France, Germany, Italy, Japan and Russia. Each member has their own important things that they want to talk about and everyone gets to share their ideas. But just like when you play with your friends, sometimes someone has to be in charge and lead the group. In the G8, it's the country that is hosting the meeting that gets to lead the group.
So, that's G8 in a nutshell. It's just like when you and your friends get together to come up with ideas on how to make things better, but the G8 is with countries and they focus on big important things.