The United States Supreme Court is the highest court in the United States. Lower courts on the federal level include the US Courts of Appeals, US District Courts, the US Court of Claims, and the US Court of International Trade and US Bankruptcy Courts. Federal courts hear cases involving matters related to the United States Constitution, other federal laws and regulations, and certain matters that involve parties from different states or countries and large sums of money in dispute.
Each state has its own judicial system that includes trial and appellate courts. The highest court in each state is often referred to as the “supreme” court, although there are some exceptions to this rule, for example, the New York Court of Appeals or the Maryland Court of Appeals. State courts generally hear cases involving state constitutional matters, state law and regulations, although state courts may also generally hear cases involving federal laws. States also usually have courts that handle only a specific subset of legal matters, such as family law and probate.
Case law, also known as precedent or common law, is the body of prior judicial decisions that guide judges deciding issues before them. Depending on the relationship between the deciding court and the precedent, case law may be binding or merely persuasive. For example, a decision by the US Court of Appeals for the Fifth Circuit is binding on all federal district courts within the Fifth Circuit, but a court sitting in California (whether a federal or state court) is not strictly bound to follow the Fifth Circuit’s prior decision. Similarly, a decision by one district court in New York is not binding on another district court, but the original court’s reasoning might help guide the second court in reaching its decision.
Decisions by the US Supreme Court are binding on all federal and state courts.