``Cognizance`` is the sine qua non of a criminal trial. The term ``Cognizance`` has not been defined under the Code of Criminal Procedure. The book explores the concept of ``Cognizance`` and its other facets. An effort has been made to have a glimpse of the powers of a Magistrate to take cognizance in a complaint case; on police report; upon information received/own knowledge; limitation on such power and exceptions thereof. The powers of a Sessions Court to take cognizance have also been analysed succinctly.