The init process is the first process that the kernel executes, after booting the system, having pid 1. All other process either are created from init process or by processes created from init process. If a process turns into a zombie process, then it is terminated by the init process. Init process is the grandparent of all the processes. The kernel looks for the init process in the following order:-
/sbin/init: The preferred and most likely the location for init process.
/etc/init: Another likely location for the init process.
/bin/init: A possible location for the init process.
/bin/sh: The location of the bourne shell, which the kernel tries to run if it fails to find an init process.
The first of these processes, that exists is located as the init process. If all the four processes fail to execute, the Linux kernel halts the system with a panic.
