Definitions:
- Justia: Judicial power is the power “of a court to decide and pronounce a judgment and carry it into effect between persons and parties who bring a case before it for decision.” It is “the right to determine actual controversies arising between diverse litigants, duly instituted in courts of proper jurisdiction.” The terms “judicial power” and “jurisdiction” are frequently used interchangeably, with “jurisdiction” defined as the power to hear and determine the subject matter in controversy between parties to a suit or as the “power to entertain the suit, consider the merits and render a binding decision thereon.” The cases and commentary however, support, indeed require, a distinction between the two concepts.
- Wikipedia: The judiciary is the system of courts that interprets, defends, and applies the law in the name of the state. The judiciary can also be thought of as the mechanism for the resolution of disputes. Under the doctrine of the separation of powers, the judiciary generally does not make statutory law (which is the responsibility of the legislature) or enforce law (which is the responsibility of the executive), but rather interprets, defends, and applies the law to the facts of each case. However, in some countries the judiciary does make common law.
In many jurisdictions the judicial branch has the power to change laws through the process of judicial review. Courts with judicial review power may annul the laws and rules of the state when it finds them incompatible with a higher norm, such as primary legislation, the provisions of the constitution, treaties or international law. Judges constitute a critical force for interpretation and implementation of a constitution, thus in common law countries creating the body of constitutional law.
- NCSL: Every society has confronted the question of how to resolve disputes. Many early societies chose a private system of revenge for dispute resolution but, as civilizations evolved, communities began designating individuals to resolve disputes impartially in accordance with established norms and customs.
In Ancient Greece, rulers and a group of respected elders in the community were empowered to hear disputes. The judicial powers of these institutions were gradually replaced by an assembly of 6,000 jurors that was divided into smaller panels to hear particular cases.
Juries played a key role in the development of the English judicial system. As more legal disputes were submitted to juries for resolution, however, concerns arose that both judges and juries were rendering biased decisions based on irrelevant and untrustworthy evidence. Trial procedures often were deemed haphazard, arbitrary and unfair. The concerns about the English judicial system affected the development of the U.S. judicial system.
The general blueprint for the U.S. judiciary is laid out in Article III of the U.S. Constitution, and many details of federal judicial power are spelled out in the Judiciary Act of 1789. State judicial systems are created similarly by state constitutional and statutory provisions.
One of the principal characteristics of the U.S. judicial system is that it has a specific role under the separation-of-powers doctrine. Under the doctrine, laws are passed by the legislature and enforced by the executive branch. The judiciary interprets and applies the law, adjudicates legal disputes and otherwise administers justice. This includes the authority to enforce—or void—statutes when disputes arise over their scope or constitutionality.
The power of the judiciary is balanced by the legislature's ability to pass new laws and propose constitutional amendments. Legislatures also may have the power to confirm, select or impeach judicial branch officials.
