The G20, or Group of Twenty, is a club of countries whose leaders get together to discuss plans for the global economy. Increasingly, they also touch on other important topics like climate change.

Between them, G20 countries account for 85% of the world's economic output and 75% of world trade

. They also contain two-thirds of the global population.

The members are the European Union and 19 nations - Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the UK and the US. Spain is always invited as a guest.

The summit is also an opportunity for national leaders to meet on the sidelines for one-to-one discussions, in the manner of US President Biden and President Xi of China right now.