Raw data is handy feature that allows developers to take a look at the field group configuration. Clicking the “Data” button will open a modal with the Field Group settings splitted in two parts:
Render this title on edit post screen
Field groups with a lower order will appear first
Shown in field group list
Select items to hide them from the edit screen.
Select user roles that are allowed to view and edit this field group in post edition
Add custom meta data to the field group.
Add personal note. Only visible to administrators