The Queen, on the advice of the Lord Chancellor, appoints High Court judges; this is the same for circuit judges and recorders.
There are of course minimum requirements for judges to be qualified to take such a role.
Courts act as the adjudicators in cases that involve public law.
They are frequently asked to determine a case where a public body has infringed the rights of a private individual and are required to rule on the legality of a decision made by a public body.
 2 AC 513 Unlike in other countries, the courts are constrained by the principle of parliamentary sovereignty and are unable to strike out primary legislation as unconstitutional. Courts have also provided 'advisory opinions' in situations that do not disclose any live disputes; but present an answer to a hypothetical question of law responding in a way that would answer the question as to whether such a given set of facts were to arise, what in these circumstances would be lawful.
The courts’ powers to uphold constitutional principles, such as the rule of law or the separation of powers, are limited by contrary provisions within an Act of Parliament.  AC 789 The emphasis of such advisory opinions is upon public functions, and the aim is to make certain that public bodies act in the public interest.
The role of the court system is to decide cases, including a determination of the relevant facts, then the determination of the relevant law and the application of the relevant facts to the relevant law.
The courts must ascertain what the relevant facts are; this may require a court to resolve a dispute about the facts.
It is exceptional that a person is appointed to a senior judicial position than through promotion through the other judicial positions. Judicial Appointments Commission The widespread criticism of the lack of transparency in the judicial appointments process was the impetus for the passage of the Constitutional Reform Act 2005.
The Judicial Appointments Commission (JAC) was established by an Order in Council in April 2006 to review judicial appointments.