Think it's a "process Graph"... and Process ID 1 is systemd on the[/her] machine. Edit: turns Out, she explains: [...]systemd: rkt will run a program called systemd-nspawn as the init (PID 1) process inside your container. This is because it can be bad to run an arbitrary process as PID 1[0] -- your process isn't expecting it and will might react badly. It also run some systemd-journal process? I don't know what that's for yet.[...]"

[0] https://engineeringblog.yelp.com/2016/01/dumb-init-an-init-f...