A supreme court is the highest court within the hierarchy of many legal jurisdictions. Other descriptions for such courts include court of last resort, instance court, judgment court, apex court, and highest court of appeal. Broadly speaking, the decisions of a supreme court are not subject to further review by any other court. Supreme courts typically function primarily as appellate courts, hearing appeals from decisions of lower trial courts, or from intermediate-level appellate courts.
However, not all highest courts are named as such. Civil law states tend not to have a single highest court. Additionally, the highest court in some jurisdictions is not named the "Supreme Court", for example, the High Court of Australia; this is because decisions by the High Court could formerly be appealed to the Privy Council. On the other hand, in some places the court named the "Supreme Court" is not in fact the highest court; examples include the New York Supreme Court, the Supreme Courts of several Canadian provinces/territories and the former Supreme Court of Judicature of England and Wales, which are all subordinate to higher courts of appeal.
Some countries have multiple "supreme courts" whose respective jurisdictions have different geographical extents, or which are restricted to particular areas of law. In particular, countries with a federal system of government typically have both a federal supreme court (such as the Supreme Court of the United States), and supreme courts for each member state (such as the Supreme Court of Nevada), with the former having jurisdiction over the latter only to the extent that the federal constitution extends federal law over state law. Jurisdictions with a civil law system often have a hierarchy of administrative courts separate from the ordinary courts, headed by a supreme administrative court as is the case in the Netherlands. A number of jurisdictions also maintain a separate constitutional court (first developed in the Czechoslovak Constitution of 1920), such as Austria, France, Germany, Luxembourg, Portugal, Spain and South Africa. Within the former British Empire, the highest court within a colony was often called the "Supreme Court", even though appeals could be made from that court to the United Kingdom's Privy Council (based in London). A number of Commonwealth jurisdictions retain this system, but many others have reconstituted their own highest court as a court of last resort, with the right of appeal to the Privy Council being abolished.
In jurisdictions using a common law system, the doctrine of stare decisis applies, whereby the principles applied by the supreme court in its decisions are binding upon all lower courts; this is intended to apply a uniform interpretation and implementation of the law. In civil law jurisdictions the doctrine of stare decisis is not generally considered to apply, so the decisions of the supreme court are not necessarily binding beyond the immediate case before it; however, in practice the decisions of the supreme court usually provide a very strong precedent, or jurisprudence constante, for both itself and all lower courts.