The Supreme Court was created under the terms of the Constitutional Reform Act 2005, and completes the separation of the UK's legal and judicial systems. Justices of the Supreme Court will no longer be able to sit or vote in the House of Lords.
Slightly confusingly, the High Court, Court of Appeal and Crown Court have up to now been referred to as the Supreme Court of Judicature of Northern Ireland – due to the introduction of the new Supreme Court they are now known as the Court of Judicature of Northern Ireland.
Additional information can be found on The Supreme Court website.