Definition: S.2. (c) (Cr.P.C.) Cognizable offence means an offence for which, and cognizable case means, a case in which, a police officer may, in accordance with the First Schedule or under any other law for the time bell in force, arrest without warrant.
Cognizable offences are usually serious in nature. (For full details the visitor is advised to see First Schedule of Cr.P.C.)
Sec. 154 Cr.P.C. provides that the Police Officer has to receive FIR relating to cognizable offences without Magistrate's permission, and enters it in General Diary and immediately starts investigation.
The Police may arrest the accused, in cognizable offence without warrant.
In cognizable offences, police has a duty to investigate the case without seeking permission from the Magistrate.