What is the difference between the Process: and Main PID: lines in the output of systemctl status on a service unit?  What does the process number denote?For example:In the output from systemctl status sshd we see a line with Process: above the line saying Main PID:.  It has a different process number than the Main PID: line.  Here's one from a RHEL admin guide:  # systemctl status sshdsshd.service - OpenSSH server daemon   Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled)   Active: active (running) since Mon 2014-09-01 09:35:17 EST; 2s ago  Process: 6191 ExecStartPre=/usr/sbin/sshd-keygen (code=exited, status=0/SUCCESS) Main PID: 6194 (sshd)   CGroup: /system.slice/sshd.service           6194 /usr/sbin/sshd -DI'm trying to understand what that process number is.
What is the difference between Process: and Main PID: in the output of systemctl status?
systemd