Almost all the constitutions of the world have a Preamble. The Preamble to a Constitution sets out the main objectives, which the legislation is intended to achieve. As the Supreme Court has observed, the Preamble is a key to unravel the minds of the makers of the Constitution. It serves as an introduction to the Constitution and shows the general purpose for which the Constituent Assembly made the several provisions in the Constitution. It also embodies the ideals and aspirations of the people of India. It provides the essence of the Constitution and in a - nut shall it reveals what the Constitution is all about.

The Preamble is not regarded as the source of any substantive governmental power and cannot place any limitations on the exercise of the powers of the organs of the Constitution, viz the Executive, Legislature and Judiciary. The Preamble cannot override the express provisions of the Constitution. It cannot be enforced in a court of law. It has limited application and can be resorted to only what there is an ambiguity in the provisions of the constitution. According to the Supreme Court, if the terms used in the provisions of the Constitution are ambiguous or capable of two or more meanings, some assistance can be taken from the Preamble. In such cases the interpretation, which fits the Preamble, may be preferred.

Important features of Indian Constitution Preamble

• It is preface or the introduction to the Constitution. It is not an integral part of constitution. 
• Thus, preamble is not a part of the Constitution of India as it is not enforceable in a court of law. However, the Supreme Court has, in the case of 'Kesavananda Bharati v. State of Kerala', recognized that the Preamble is a part of the Constitution and may be used to interpret ambiguous areas of the Constitution
• The `Objective Resolution’, proposed by Pandit Nehru and passed by the Constituent Assembly ultimately became the Preamble.
• The idea of preamble was borrowed from the Constitution of USA.
• The words `SOCIALIST’, `SECULAR’ and `INTEGRITY’ were added by the 42nd Amendment in 1976.
• Sovereign means free to follow internal and external policies. Socialist means no concentration of power and money. Secular means no particular religion. Democratic means elected representatives. Republic means no room for hereditary ruler or monarch.