Judicial Power
Judicial power is the authority to decide cases — to interpret and apply the law to real disputes and issue binding judgments. Article III vests "the judicial Power of the United States" in one supreme Court and the inferior courts Congress creates, and Article III, Section 2 defines its boundaries: the federal judicial power extends to cases arising under the Constitution, federal laws, and treaties, and to specified parties and subject matters (such as admiralty and disputes between states). The power is exercised only in "Cases" and "Controversies" — courts decide concrete disputes, not abstract questions.
Judicial power is the authority to decide cases — to interpret and apply the law to real disputes and issue binding judgments. Article III vests “the judicial Power of the United States” in one supreme Court and the inferior courts Congress creates, and Article III, Section 2 defines its boundaries: the federal judicial power extends to cases arising under the Constitution, federal laws, and treaties, and to specified parties and subject matters (such as admiralty and disputes between states). The power is exercised only in “Cases” and “Controversies” — courts decide concrete disputes, not abstract questions.
Example: Article III, Section 2 of the Constitution enumerates what the judicial power covers: “The judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution, the Laws of the United States, and Treaties made…” — listing admiralty, controversies between states, and cases affecting ambassadors, among other heads of jurisdiction.
Common misconception: Judicial power does not include enforcement. Federal courts say what the law is in a case and order relief, but they have no army, agency, or purse; their judgments depend on the executive branch to carry them out — a deliberate feature of separated powers.