Final answer:
An amicus curiae ('friend of the court') brief is submitted by parties not directly involved in a case but interested in the outcome, aiming to provide information and influence the court's decision.
Step-by-step explanation:
A brief that is filed by an interested party who is not directly related to a case is known as an amicus curiae brief, or a 'friend of the court' brief.
This type of brief is submitted by individuals or interest groups who are not plaintiffs or defendants in the case but have a strong interest in the case's outcome. The intent of an amicus curiae brief is to offer information, expertise, or insight that has a bearing on the issues in the case, thereby assisting the court in making a more informed decision.
Interest groups often use amicus curiae briefs as a form of judicial lobbying, seeking to influence court decisions in a way that aligns with their goals or concerns. These briefs can provide the court with broader context on how its decisions might affect public policy, societal issues, or the interests represented by the group.