The article is about the concept of the Deterrent theory of Punishment. It means that severe punishment should be set for a crime so that it put fear in the minds of the people so the crime is not repeated again. It helps in deterring/reducing the attempt of committing any crime. This concept is simplified by authors like Thomas Hobbes, Cesare Beccaria, and Jeremy Bentham. All the different theories and introductions given by these philosophers 3 components came into knowledge namely Severity, Certainty, and Celerity. This theory is divided into three categories called General deterrence, Specific Deterrence, and Incapacitation. Case laws like the Nirbhaya gang rape case, Phul Singh v. State of Haryana, Ballo alias Balveer v. the State of Rajasthan, and State of HP v. Nirmala Devi. I have read all theories of punishment and to know more and understand this particular theory I have researched and wrote this article. After reading several articles and research papers and reading about these tough and severe punishments used in different countries, I found out that this theory has no implication in this modern world. Just because of the laws of different countries many innocents are punished with the guilty ones.