The Supreme Court is being talked about a lot recently.
That's mainly because it's about to consider whether Boris Johnson's decision to suspend Parliament for five weeks is legal.
But what is the Supreme Court, and what does it do?
It is the highest court in the United Kingdom.
The judges, who are also know as justices, have the final say on the biggest legal issues across England, Scotland, Wales and Northern Ireland.
It's in London and is opposite the Houses of Parliament.
It is the final court of appeal, which means that if other courts disagree or can't make decisions, the Supreme Court will have the final say.
The Supreme Court will give the final verdict in all types of cases in the United Kingdom, but not criminal matters in Scotland.
The justices are appointed by the Queen, and they're recommended to her by a panel of legal experts from each of the UK's nations.
The applicants must have been a High Court judge for at least two years or a practising lawyer for 15 years.