Hi Mille
I think you ask about the CS3 and the latest update.
All that follows suppose that your CS3 is linked to your PC either directly or through a WiFi router.

VNC allows you to have a remote view of the CS3 screen on your PC
- you may take remotely control of your trains from your PC or make screen copies

WebBrowser Allows you also to take control of your CS3 from your PC
- in this case, this is not a screen copy but rather a larger view of your CS3 (NOT a screen copy)
- in this case there is a different user access (i.e.: the images on the CS3 and your PC are different and sometimes interlocked (e.g.: if you edit a loco on the web Browser, the fonction is not available on the CS3 (until you are finished doing it on the PC
- you CANNOT have screen copies of your CS3 because the images are DIFFERENT (e.g.: a larger layout)
- some fonctions are NOT available like the fonction mapping

Mobile device control
- this fonction works only if your CS3 is connected to a WiFi router
- a regular smartphone (iPhone 11 in my case) allows to control locos, point switches, view the layout, start events

Old application CS2.exe
- all fonctions of this Märklin-prepared application are OK to work with a CS3 with the exception of the LAYOUT (which will cause the application to terminate

Cheers
Jean

Yes.
You can do exactly the same in VNC as you can directly from the CS3 itself.
Best regards
Per