Brexit is the forthcoming withdrawal of the United Kingdom (UK) from the European Union (EU). In the June 2016 referendum, 52% voted to leave the EU, leading into a complex separation process implying political and economic changes for the UK and other countries. The timetable for withdrawal has not yet been firmly established - wikipedia
Withdrawal from the European Union has been a right under Article 50 of the Treaty on European Union of EU member states since 2007. The details of the process for the UK's withdrawal are uncertain under EU law – Article 50, which now governs the withdrawal, has never been used before. Unless extensions are agreed, the timing for leaving under the article is two years from when Britain gives official notice, but this official notice was not given immediately following the referendum in June 2016. The assumption is that during the two-year window new agreements will be negotiated, but there is no requirement that there be new agreements.
Withdrawal has been the goal of various individuals, advocacy groups, and political parties since the UK joined the European Economic Community (EEC), the predecessor of the EU, in 1973, though continued membership of the EEC was approved in a 1975 referendum by 67% of voters.