Many difficult keywords or terms have been used in Preamble. Let us understand these Keywords one by one.

Preamble starts with the expression WE THE PEOPLE OF INDIA. 

In the preamble the nature of the Indian State is mentioned to be Sovereign, Socialist, Secular, Democratic, and Republic. 

1. Sovereign: is a nation which is independent and which has no interference of external powers in management of its internal matters. 

2. Socialist:  Socialist is the nation in which the means of ownership are owned by government with the objective of welfare of masses. We have our own definition of socialism which is different from general definition of socialism. Though we have adopted goals of socialism such as welfare of masses but we have not adopted any rigid model of state (public) ownership only. In our form of socialism, both public as well as private sectors co-exist to attain welfare of masses. 

3. Secular: A secular state is a state which treats people belonging to different religions in the same manner. In Indian secularism, state does not favour people belonging to one religion but is involved in promotion of all the religions equally. Thus, In India, we have positive form of secularism 

i.e. state is neutral to all religions and it engages in promotion of all the religions equally. In other nations which are also secular such as France, state does not engage in promotion of religion and even restricts the freedom of practising religion in public life. Another example of secularism is ex-USSR where the practice of religion even in private life was prohibited. 

4. Democracy: ‘Demo’ means people and ‘cracy’means rule. Democracy literally means ‘rule of people’. There are two kinds of democracy: direct and indirect. In a direct democracy, people themselves take decisions on various issues. In indirect or representative democracy, people elect their representatives to form the Government. These representatives are chosen through free and fair elections. These representatives decide on behalf of the people. Ours is a representative democracy. 

The democratic principles are highlighted with Article 326 which deals about right to vote and Article 75 (3) which means about collective responsibility of council of ministers to people. 

5. Republic: It is a form of Government in which the head of a State is elected. For example: In India, both real head i.e. Prime minster and nominal head i.e. President are elected. The opposite to Republic is Monarchy. ‘Mono’ means single and ‘archy’ means head. Thus, a monarch is a single head of State. Usually the monarchy is through heredity.

We have learnt that the nature of India state is Sovereign, Socialist, Secular, Democratic and Republic. We have adopted this nature of Indian State to fulfil certain aspirations for Indian citizens. 

1. Justice: The term ‘Justice’ in the Preamble embraces three distinct forms, namely:

 

a. Social Justice: Social justice refers to the absence of discrimination and equal status for everyone in the society. 

b. Economic Justice: Economic Justice refers to equal opportunity to everyone to make a living and to improve one’s standard of living. 

c. Political Justice: Political justice refers to equal opportunity to everyone to contest elections and to vote in elections. 

2. Liberty:  

Liberty of 

a. Thought 

b. Expression 

c. Belief and faith 

d. Worship

3. Equality: of 

  

a. Status  b. Opportunity 

‘Equality’ means the absence of special privileges to any section of society and provision of adequate opportunities for all individuals without any discrimination. It does not mean equal distribution of wealth among all the individuals. Further, preamble states that after retaining equality of status and opportunity the state shall promote all the individuals. 

4. Fraternity: Fraternity refers to brotherhood. 

The constitution promotes this feeling of fraternity by the system of single citizenship.

 The Preamble declares that fraternity has to assure two things – the dignity of an individual and the unity and integrity of the nation.

The Preamble performs the multifaceted roles. As mentioned, preamble specifies the source of authority of constitution, the nature of Indian state, the aspirations for the citizens,and the date of adoption of constitution. 

Apart from the above roles, Preamble also acts as introduction to the constitution and it discusses the objectives of the constitution. 

It also guides the various organs of the State regarding the ideals of Indian Polity. For instance, Preamble is used by judiciary to make appropriate interpretation of provisions of constitution and other laws.

1. Socialist 

The word socialist was inserted by 42nd Amendment Act 1976 it means control of states over the means of production. Indian form of socialism is a "democratic socialism" and not a "communistic socialism".

Democratic socialism give importance to mixed economy where public & private sectors co-exist side by side. The word socialism has been used in the context of economic planning. The idea of socialism is mainly incorporated in part IV of the Constitution that is "Directive Principles of the State Policy" in 

D.S.Nakra vs. Union of India, aim of socialist state defined as to eliminate irregularity in income, ensure decent standard of life to working people and to provide security basic framework.

The Supreme Court said that the Preamble shows the overall purposes behind the several provisions within the Constitution, and is thus a key to the minds of the manufacturers of the Constitution. Further, where the terms utilised in any article are ambiguous or capable of quite one meaning, some assistance at interpretation could also be taken from the objectives enshrined within the Preamble.

Despite this recognition of the importance of the Preamble, the Supreme Court held that the Preamble isn't a component of the Constitution. it's also not the source to ban the ability, which is given explicitly within the Constitution. Further, the Preamble isn't enforceable during a Court of Law. 

In the Kesavananda Bharati case (1973), the Supreme Court rejected the sooner opinion (in the Berubari Case) and held that the Preamble may be a a part of the Constitution. 

It observed that the Preamble is of utmost importance and also the Constitution should be read and interpreted within the light of the grand and noble vision expressed within the Preamble. Explanation provided by the Supreme Court: 

The Preamble was enacted after remainder of the Constitution was already enacted. The Preamble was inserted within the end to make sure that there's no inconsistency between the Preamble and other provisions of the Constitution. This was unlike USA where the Preamble was enacted first. 

The question regarding the amenability of the Preamble was raised within the Kesavananda Bharati Case (1973). The argument of the petitioner was that the Preamble isn't a provision of the Constitution, hence it can't be amended. Supreme Court’s view: Preamble is a necessary and integral a part of the Constitution. Hence, it is amended; otherwise the harmony of the Constitution may get disturbed. It held that the Preamble can be amended, subject to the condition that no amendment is completed to the ‘basic features’ of the Constitution. Consequently the Preamble was amended by the 42nd Amendment Act, 1976. It added three new words: Socialist, Secular and Integrity to the Preamble.