There is no term like FIR in criminal procedure code. FIR stands for First Information Report,it is lodged by police office only in the case where cognizable offence committed. Cognizable offences are more serious than non-cognizable offence. It is the right of every person, that in case of cognizable offence, FIR can be filed by him and police officer does not have any discretion where the cognizable offence is committed,even if it does not come under his jurisdiction. Information regarding cognizable offence is defined under section 154 of criminal procedure code. After lodging the FIR, the police officer ensure that whether the information is regarding cognizable offence.once once FIR is filed,he can start the investigation without the permission of the magistrate and can arrest any suspected person for further investigation, such person should be presented before the magistrate within the completion of 24hrs .
The information that is given by the informant shall be reduced into writing and one copy of that FIR will also be given to the informant. The informant is required to sign. After completion of the investigation, he will send a police report to the magistrate for cognizance under section 190 of Cr. P.C. After cognizance if accused refuses the said charges then the trial will start.