What does case law provide in legal matters?

Case law refers to the body of law that emerges from the judgments and decisions of courts, particularly appellate courts. It is built upon the legal principles established in previous cases, creating a framework within which future cases are analyzed and decided. By choosing the correct option, which refers to an aggregate of reported cases forming jurisprudence, it highlights the development of legal precedents that guide courts in making decisions on similar issues.

This aggregation of cases allows for consistency and predictability in the law, as judges are often bound to follow the rulings of higher courts within their jurisdiction unless there is a compelling reason to deviate. This mechanism helps in shaping and evolving legal standards over time. In the context of asylum and immigration law, case law can be particularly significant as it sets precedents for how laws are applied in specific situations, impacting the outcomes of asylum claims.

The other options don't correctly represent what case law is. Legislative rules refer to statutes or written laws enacted by legislative bodies, and opinions from a single court do not provide a comprehensive understanding of established legal precedents. Additionally, summaries of legal statutes and treaties do not capture the evolving nature of jurisprudence that case law represents.