The id_rsa is a private key used in RSA cryptographysystems. It serves for secure authentication in connections, such as in SSH, providing secure access to remote systems and ensuring communication integrity.
How to use via SSH:
The first step is to grant permissions to the file id_rsa:
chmod 600 id_rsa
Afterwards, we can use it, for example, in SSH with the following command:
ssh -i id_rsa user@IP
And we would access the target machine without the need for a password.
