First Process in Linux scheduler (or) init


It is confusing that which is the first process in linux. Internet some people is telling Scheduler is the first process id 0. But some body is telling init is the first process id 1.

When i issue the command pstree -p. Scheduler process is not visible. Only process is starting from init.

Is it possible to show the scheduler process in unix?

Please let me know regarding this process.

Normally, the other name of kernel is Scheduler
after starting kernel, first user mode process starts
init starts old linux / unix (SYSV)
upstart starts for some Distru
systemd starts for CentOS7 /Redhat7 /Debian/Fedora…