Brexit refers to the United Kingdom's decision to leave the European Union. In a referendum held on June 23, 2016, citizens of the UK voted to leave the EU, and the country officially withdrew from the EU on January 31, 2020, after a prolonged and contentious negotiation process. The decision to leave the EU had significant economic, political, and social consequences for the UK and the member states of the EU, and its long-term impact is still being assessed.