The intergovernmental forum comprises 19 countries as well as the European Union.
The Bali summit will focus on three main areas — global health, digital economic transformation and energy transition.
The underlying theme of the summit is Recover Together, Recover Stronger.
But what is the G20 and why does it matter?
What is the G20?
The G20 is an all-purpose platform for diplomacy.
The group comprises Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the UK the US and the EU.
Spain is a permanent guest, as are the UN, the African Union, the Association of South-East Asian Nations (Asean) and the World Bank.
Members account for more than four-fifths of the world’s GDP, three-quarters of its trade and three-fifths of its population.
How does the summit work?
Every year, the host nation — known as the Presidency — invites guest countries and global and local organisations to participate, broadening the forum’s representation.
This year, Indonesia has invited the UAE, Singapore, Cambodia and Ukraine. The full list is yet to be released.
How often does the G20 meet?
The Presidency rotates, with the host country working together with its predecessor and successor, known as the Troika, to ensure continuity.
Italy, Indonesia, and India make this year’s Troika.
The G20 initially met twice a year, but has been meeting once a year since 2011.
Having no permanent secretariat, the group’s agenda and co-ordination is done by the leaders’ personal representatives, known as sherpas, together with finance ministers and central bank governors.
Meetings among trade ministers, finance ministers and central bank governors set the agenda and culminate into the main conference.
How does it work?
At the end of the conference, a statement of the commitments and the visions is drafted from the chosen recommendations and deliverables arrived at the meetings.
Nothing is binding, though, and there is no enforcement beyond peer pressure.
Most of what is announced at the summit has been decided in pre-summit talks between the officials who do the diplomatic work for the leaders who attend the main summit.
The G20 has often been called a gabfest, where leaders talk aplenty, but achieve very little.