The Commonwealth is a group of 54 countries from all over the world. The size of the countries varies, from the biggest in size or population, to the smallest islands with very small populations. No matter what size these countries are, they are all given an equal voice.
Her Majesty Queen Elizabeth II is the Head of the Commonwealth.
Her role is an important symbolic one. There is no maximum fixed term (the role can be for as long as the members decide) and any future Commonwealth Heads will be chosen by Commonwealth leaders.
Each country brings unique cultures, values and skills to the Commonwealth family. By sharing these wonderful differences and teaching others about them, the Commonwealth is a very rich family with many special qualities.
The Commonwealth is full of young people who make it so special. More than 60% of the Commonwealth population are under 29 years old.
Commonwealth Day is celebrated each year on the second Monday of March.
Each year a theme is chosen for the year, and Commonwealth Day is an opportunity for members to think and talk about the theme.
Every 2 years the Government Heads meet to discuss the challenges that the Commonwealth faces. They look at solutions to these challenges and agree upon which are most important.
The Commonwealth and the environment are strongly linked. Many nations within the Commonwealth have a huge diversity of wildlife and environments - from tropical rainforests in Borneo and polar ecosystems in Canada to coral reefs in Belize and grasslands in Kenya.
Many of the island nations would be directly affected by climate change and rising sea levels, meaning that it is a very real and immediate threat.
In 2015, the Queen's Commonwealth Canopy project was launched. In recognition of Her Majesty's lifetime of service to the Commonwealth, the project appeals to all 54 Commonwealth members to contribute areas of indigenous forest to be preserved for future generations.
Since the project was launched, around 35 Commonwealth countries have dedicated forestry projects or are planting new forests. Another 10 countries are working towards their plans.
Singapore was the first to offer a dedication - six hectares of rainforest in the Singapore Botanic Gardens and 163 hectares of Bukit Timah Nature Reserve Forest.