What is constitution law?

Constitutional law is a body of rules, doctrines and practices that sets out how the machinery of the Government of a State should be organized. These rules and norms decide powers and structures among different entities of a State viz. executive, legislature and judiciary; and also the powers between the central, state / provincial and local governments. Thus, constitutional law is considered as a supreme law which organizes and empowers the government. It helps in determining how other laws are made and implemented in a State. In some countries like the United States, Canada and India, it also contains the basic fundamental rights of the citizens.