Question about "Switch All Mode"

For my Z-Wave devices I find in the configuration in habmin within the section ‘Device configuration’ a function called “Switch All Mode”:

What is the functional impact of this setting? I do not really understand what it really does as some devices are excluded from all on/off while others are included (but I never set these properties on purpose). And most of all a lot of my devices which have the setting ‘Exclude from All On and All Off groups’ are actually member of groups and work perfectly with the All On and All Off Functions implemented within my items files and sitemaps files. An as the group membership is defined in item files and the All on/off-Functions are defined in my file based config I hardly see how these settings in Habmin correlate with the rest of the settings. Can anyone explain this? Thanks!

Zwave has the concept of association groups which allows the individual devices to command each other directly bypassing OH entirely. If you configure the device to turn ON/OFF for the SWITCH ALL, it will turn ON/OFF on those commands independently from OH.

Zwave groups have nothing to do with OH Groups.

Ok, I understand this, many thanks for the explanation.
But what does OH do when I switch all my lights in an OH-Group? Is it looping through all the group members and sends an individual ON/OFF-command to each device?

Yes.

Thank you very much for the clarification!