What is Constitution?
Constitutional law is a body of law which defines the role, powers, and structure of different entities within the country, namely, the executive, the parliament or legislature, and the judiciary; as well as the basic rights of citizens and, in federal countries such as the United States and Canada, the relationship between the central government and state, provincial, or territorial governments.

Not all nation states have codified constitutions, though all such states have a jus commune, or law of the land, that may consist of a variety of imperative and consensual rules. These may include customary law, conventions, statutory law, judge-made law, or international rules and norms.

Constitutional law deals with the fundamental principles by which the government exercises its authority. In some instances, these principles grant specific powers to the government, such as the power to tax and spend for the welfare of the population. Other times, constitutional principles act to place limits on what the government can do, such as prohibiting the arrest of an individual without sufficient cause.

In most nations, such as the United States, India, and Singapore, constitutional law is based on the text of a document ratified at the time the nation came into being. Other constitutions, notably that of the United Kingdom, rely heavily on unwritten rules known as constitutional conventions; their status within constitutional law varies, and the terms of conventions are in some cases strongly contested.

Constitution law governs the relationships between the judiciary, the legislature and the executive with the bodies under its authority. One of the key tasks of constitutions within this context is to indicate hierarchies and relationships of power. When a constitution establishes a federal state, it will identify the several levels of government coexisting with exclusive or shared areas of jurisdiction over lawmaking, application and enforcement. Some federal states, most notably the United States, have separate and parallel federal and state judiciaries, with each having its own hierarchy of courts with a supreme court for each state. India, on the other hand, has one judiciary divided into district courts, high courts, and the Supreme Court of India.
The role of constitution is multifarious and the need and functions of constitution keeps on changing with time. constitution is a living document as it can be amended with time. constitution provides the required motion to the chariot of the democracy.
The need of Constitution
constitution is the sacred book of a democracy. constitution is what guides the democracy in its day today functioning. constitution is the travel itinerary of a country. Constitution can be written or unwritten as in case of India and UK respectively. the importance of constitution is summed up as follows. We need a constitution because we need a government to protect our natural rights to life, liberty, and property. The constitution is the fundamental law within which the government must operate.

Constitution is set of written rules , that are accepted by all people living together in a country, It lays down certain ideals that people as a citizen aspire to live in society ( like spread brotherhood ,and to give certain level of education to your children) or it determines the nature of the society ( like democratic)

We need protection from bad people such as murderers, oppressors, dictators, corrupt people, thieves, robbers, burglars, fraudsters, etc. and this is why we must have a government guided by constitutional law. The constitution provides a set of written rules that is authorized, and approved by the people. The constitution sets out the rules under which the government is to operate. It is important to remember that the government must protect our natural rights to life, liberty, and property in accordance only with the written constitution. In this view, the constitution creates the government; provides powers to the created government; and limits these government powers.

The government must have powers to do its job to protect life, liberty, and property. These powers are written and specified in the constitution. The government must have the following powers:
1. makes laws; Legislative (Congress)
2. implements these laws; Executive (President) – implements these laws
3. referees if there are disagreements in interpreting the laws. Judiciary (Supreme Court)

The primary functions of Constitution are as follows:
1. basic rules- it has the basic rule on which the democracy functions. it guides in functioning of a democracy

2. rights- it defines the right of a citizen over state and other persons

3. duties- it determines the duty of the state and also the duty of the individual vis a vis the country.

4. directives- it contains the directives to the government to make law

5. determines the territory of state and country- the constitution limits the territory of the whole country and the states.

6. citizenship- it determines the various provisions for gaining and losing citizenship of the country.

7. Centre and states relations- constitution determines the legislative, judicial, and executive relations between central government and states.

8. constitutional posts- it mentions power functions of president vis a vis PM.

9. Rule of law: it is the bulwark of rule of law in a country it gives the true color to right to equality, freedom and liberty.

10. Check and balance: it makes sure to check and balance power of one organ over the other.

11. Base of democracy: it defines whether the democracy is direct or indirect and if it is indirect then whether it is presidential or parliamentary system.

12. Political system: It defines the nature of country’s political system (like federal, secular, socialistic and democratic in India)

13. Protection and rights: To ensure that dominant group don’t use its power against others or minorities so minorities have been given certain special protection and rights

14. Protection from self: It saves us from ourselves – sometime we strongly feel about any issue that might go against our largest interest like sometime we think that India needs any dictatorship against democracy for to resolve some issue (like terrorism)

15. Public aspiration: It enables the government to fulfill the aspiration of society and create condition for a just society. (everyone has been put equal before law and there is rule of law)

16. Identity: It gives fundamental identity of the people the country (like democratic in nature)

17. Institutional balance: It balance institutional design and make specification of decision-making powers (like separation of power between various organs of gov. ie-executive, judiciary, legislative, many constitutional bodies and offices. …and separations of power between various level of gov. ie – national, state, local level)

18. Reference: It gives us reference for right and wrong, what/whom to follow when in doubt. So basically, acts as reference book.

19. Coordination: it allows minimal coordination among member of a society

20. Rule of election: It specifies how the rulers are to be chosen and what the gov. Are empowered to do and what not to do.

21. Relationship: It determines the relationship between state to people and people to people.

22. Minority rights: It gives at least something to every person, group, society to stick to the constitution and hope something better …. like there are separate positive provision for minority group, woman, weaker section of the society

23. Fundamental rights: It gives fundamental rights to people so that state could not go against the desire of the people…. What will happen if you have money but no proper budget to spend it? Same is with the constitution it has provisions of budget management for the proper working of the country financially.

     1. What if you want to visit some place and some people stop you without any reason? It is ensured by Fundamental rights in the Constitution.

     2. What if some foreign power invade you and you have no proper Army to stop them? If no Constitution, there is no provision of payment, no Army?

24. A Constitution is needed and found in non-democratic governments also but it is a prerequisite in a democracy (No Prime Minister, No President, No Chief Minister, nothing without Constitution, because the Constitution is the soul of a democracy.)

25. Elected government: If a party has won in an election, it doesn’t mean that it is free to rule the country according to its wish. Even an elected government has to rule the state or the country according to its Constitution which ensures development of all its citizens.

26. Safety: Because of our Constitution minorities feel safe in our country as it doesn’t allow majoritarianism.

So slowly constitution becomes the part and partial of citizen of nation and citizen starts thinking on constitutional way and aspire to live in society that constitution recognize.
role of constitution is multifarious and the need and functions of constitution keeps on changing with time. constitution is a living document as it can be amended with time. Constitution provides the required motion to the chariot of the democracy.