Brexit is when the people of the United Kingdom voted to leave the European Union which is a group of countries that have agreed to make rules together and trade with each other like a team. Some people wanted the UK to stay part of the team, but many people wanted to leave because they thought the rules made by the European Union were too strict and were taking away their freedom. In the end, the people of the United Kingdom voted to leave the European Union, which is why it is called Brexit.