LEAP 15.2 VNCserver vs VNCmanager persistant

Hello there,
As seen in this guide, there are 2 different persistent VNC server sessions:

1. VNC Session Initiated Using vncserver
2. VNC Session Initiated Using vncmanager

I can't figure out what is the difference, in the guide, I find the explanation of vncserver not clear to me and there is no comment on the vncmanager.

My use-case is:
I have a local desktop that I switch on/off every day running Opensuse 15.2 Mate DE.
I have a remote (in another room) laptop running Opensuse 15.2 Mate DE always on. Applications are running on and sometime I go to this laptop and work with it.
Both are connected on the local LAN.
I want to have access to the laptop DE from the desktop in the current running DE to control, start, stop, manage the running applications and use the DE as if I am in front of the laptop. When I disconnect the running applications should carry on.

Could you let me know what I can do and can't with both of type?
Many thanks