Does init or systemd start gdm3 during boot?

Hi everyone,

Im quite new to Linux and for sure to PureOS and actually still trying to learn what happens in my laptop after I hit the power button, so please excuse me if this question has an obvious answer.

So I thought, that the init process would start a scheduler, which is systemd and that would then start gdm3. So if i do 'pstree" I get a tree starting from systemd and that has a gdm3 branch directly attached. Makes sense. But if I do “ps -eF” I get sbin/init with PPID 0 and /usr/sbin/gdm3 with PPID 1. Doesnt that mean, that gdm3 is a direct child of init? Or does systemd somehow telll initi to start gdm3?


in PureOS /sbin/init is the same as systemd:

dwaff@ayers2:~$ ls -l /sbin/init
lrwxrwxrwx 1 root root 20 Dec 22  2019 /sbin/init -> /lib/systemd/systemd

pstree and ps present the same information differently: ps displays process name as it was called with, while pstree with default options will dig to actual executable file in order to group the same executables together.