A more thorough explanation:

Definition: En banc is a legal term that means "on the bench." It refers to a special procedure where all judges of a particular court hear a case. This procedure is used when the court believes that the matters are especially complex or important.

For example, in the case of Calderon v. Thompson, the United States Supreme Court used the en banc procedure to review the case. This case involved complex legal issues that required the input of all the judges on the court.

The en banc procedure is not used very often in the United States. Instead, the appellate court usually takes a panel of judges to review a case. However, when a case is particularly complex or important, the en banc procedure may be used to ensure that all judges have a say in the decision.