According to the Black’s Law Dictionary, “Right to Privacy is the right that determines the non intervention of secret surveillance and the protection of an individual’s information. It is split into 4 categories
(1) Physical: An imposition whereby another individual is restricted from experiencing an individual or a situation.
(2) Decisional: The imposition of a restriction that is exclusive to an entity.
(3) Informational: The prevention of searching for unknown information and
(4) Dispositional: The prevention of attempts made to get to know the state of mind of an individual.
The right to privacy is nowhere explicitly defined in the Constitution or any other statute, it is subject to the Judicial Interpretation. In layman’s language, right to privacy means the right to be left alone. It means the right to live freely without any restrictions and interference.
The journey of Right to Privacy from a legal right to Constitutional right has been very long. The first case in which the issue of privacy was raised was in M.P. Sharma v Satish Chandra (here in after M.P. Sharma Case) were Supreme Court on the issue of ‘power of search and seizure’ held that they cannot bring privacy as the fundamental right because it is something alien to Indian Constitution.
The next case was Govind v State of MP , where the right to privacy was discussed in detail. The issue was quite similar to Kharak Singh v State of UP, but this time the approach of judgment was rather different. They upheld the validity of Madhya Pradesh Police Regulations, 855 and 856, made under Section 46(2) (c) of Police Act, 1961, under the reasonable restriction. Judges were unable to decide that whether the Right to Privacy is a fundamental right or not and they passed on the burden to the next case by saying that “The right to privacy in any event will necessarily have to go through a process of a case-by-case development”. It is right, one good concept of law cannot be developed through one case, because it is very hard to see the exceptions and consequences of that concept of law through one case.
R. Rajagopal alias R. R. Gopal v State of Tamil Nadu  was the first case which explained the evolution and scope of right to privacy in detail. In order to attain this question, Supreme Court went through the entire jurisprudence of right to privacy, its evolution and scope; and this fulfills gaps of Govind Case. To explain evolution it mainly discussed the Govind Case and follows a similar approach. This Court held that the right to privacy is implicit in the right to life and liberty guaranteed by Article 21. Reached on the conclusion, that right to privacy no longer subsists in case of matter of public record .
People’s Union for Civil Liberties (PUCL) v Union of India is related to phone tapping and it discussed that whether telephone tapping is an infringement of right to privacy under Article 21. Supreme Court argued that conversations on the telephone are often of an intimate and confidential character and telephone conversation is a part of modern man’s life. Supreme Court also said that whether right to privacy can be claimed or has been infringed in a given case would depend on the facts of the said case.
The main case which has been a landmark judgment and has a historical implication is Justice K.S.Puttaswamy and ors. v. Union of India and Ors. in which the issue of linkage of Aadhar card details has been held as a sheer violation of Right to Privacy. A nine-judge bench of the Supreme Court of India held unanimously that the right to privacy was a constitutionally protected right in India, as well as being incidental to other freedoms guaranteed by the Indian Constitution. The case, brought by retired High Court Judge Puttaswamy, challenged the Government’s proposed scheme for a uniform biometrics-based identity card which would be mandatory for access to government services and benefits. The Government argued that the Constitution did not grant specific protection for the right to privacy. The Court reasoned that privacy is an incident of fundamental freedom or liberty guaranteed under Article 21 which provides that: “No person shall be deprived of his life or personal liberty except according to procedure established by law”.
This is a landmark case which is likely to lead to constitutional challenges to a wide range of Indian legislation, for example legislation criminalizing same-sex relationships as well as bans on beef and alcohol consumption in many Indian States. Observers also expect the Indian Government to establish a data protection regime to protect the privacy of the individual. Further, the case is likely to be of wider significance as privacy campaigners use it to pursue the constitutional debate over privacy in other countries.
In a nutshell, the issue of privacy has always been debatable. In earlier cases the Judiciary failed to include the Right to Privacy as a Constitutional Right. The Judges felt that Right to Privacy is an International Concept and is alien to the country. There was a long journey for the country to reach to the Constitutionality of Right to Privacy. But gradually with the increasing leakage of personal data the need to recognize the Constitutionality of this Right became important. In many cases the Right to privacy was included as an essential and integral part under Article 21. The Justice K.S.Puttaswamny Judgment was landmark in this regard which held that Aadhar Card is not necessary as it is a breach of Privacy and Right to Privacy is an integral part of the Constitution guaranteed under Article 21 of the Constitution.
 M. P. Sharma And Others vs Satish Chandra AIR 300, 1954 SCR 1077
 the Govind v State of MP 1964] 1 S.C.R. 332
 Kharak Singh v State of UP AIR 1295, 1964 SCR (1) 332
 R. Rajagopal alias R. R. Gopal v State of Tamil Nadu AIR 265, 1994 SCC (6) 632
 People s Union for Civil Liberties (PUCL) v Union of India (1987) 3 SCC 50