Brexit has happened. The United Kingdom is no longer part of the European Union or the European Economic Area. But in the short term, nothing really changes. The UK has entered a transition period during which it remains bound by EU rules and trade policy.
Until the end of the transition period, which is set out in the UK Withdrawal Agreement, the rights and obligations of EU law continue to apply in the UK largely as they did before, although the UK will be outside the EU’s decision making institutions. The transition period is due to end on 31 December 2020, unless both sides agree to an extension. So far, the UK Government has refused to consider a possible extension and the UK Parliament has even legislated to prohibit the Government from agreeing one. Parliament can of course undo the prohibition but, at this point, an extension looks unlikely. Under the Withdrawal Agreement any extension must be agreed with the EU by June 2020.