Meaning of judicial review
Judicial review is the power of court to decide whether a law or decision made by the government is constitutional or not. This power was established in the supreme court case Marbury v. Madison of United States. It refers to the power of the judiciary to interpret the constitution and to declare any such law or order of legislature and executive void, If it finds them in conflict with with the constitution. The doctrine of judicial review is one of the check and balance in the separation of power. Article 133 gives extraordinary power to supreme court to check constitutionality of any law and declare void if they are contrary to the constitution.
Principles of judicial review
i. Constitution is the main law of the country
ii. Supreme court has ultimate power in ruling on constitutional matters
iii. Judiciary must rule against any law that conflicts with constitution.
Judicial review is the weapons of court with which it can declare r legislative action of the legislature and administrative action of the executive unconstitutional or unlawful. This prevents parliament to pass unlawful acts and also prevents executive to impose unreasonable restrictions to its subjects. Meaning of Judicial review
Read this also : Independence of Judiciary