The G20 is a push to solve many worldwide problems. There are only 19 countries in the G20 plus a European union representative. Only the most powerful countries are allowed. This year, Brisbane are holding the exclusive event. All the countries together represent 2/3 of the worlds population, and hold 85% of the worlds money.
The G20 is used so the most powerful countries come together to talk about the most important issues in the world. Some topics that get a mention are trade, energy, jobs and many more. Most of the decisions made will most likely affect you in one way or another.