Criminal law forms the backbone of any society which regulates the behaviours of human beings in any particular society. It is the body of law that implies to crimes for which punishments are recognized. The primary objective of criminal law is to penalize criminals and maintain law and order in the society. This paper seeks to introduce the background of fundamentals of criminal laws prevailing in India, keeping in mind, the layman who might not be having the legal knowledge about the subject. It covers the meaning, objective, and the basic principle the criminal law. It also includes the basic principles of the substantive and procedural criminal law which helps even the layman to have an idea about the subject. An attempt has also been made to examine some of the theoretic concepts regarding the subject of criminal law. To keep up with current proceedings, a brief analysis regarding the recent introduction of three new criminal law bills is given in the end of this paper.