Question

what is a FIR ? Explain in details about it

Answer 1

It is generally a complaint lodged with the police by the victim of a cognizable offense or by someone on his or her behalf, but anyone can make such a report either orally or in writing to the police. ... FIR is an important document because it sets the process of criminal justice in motion.

Answer 2

What is an FIR? First Information Report (FIR) is a written document prepared by the police when they receive information about the commission of a cognizable offence. It is a report of information that reaches the police first in point of time and that is why it is called the First Information Report.
It is generally a complaint lodged with the police by the victim of a cognizable offence or by someone on his/her behalf.
Anyone can report the commission of a cognizable offence either orally
or in writing to the police. Even a telephonic message can be treated as an FIR.
Why is FIR important? An FIR is a very important document as it sets the process of criminal justice in motion. It is only after the FIR is registered in the police station that the police takes up investigation of the case.