Site Groups
Like regions, site groups can be used to organize sites. Whereas regions are intended to provide geographic organization, site groups can be used to classify sites by role or function. Also like regions, site groups can be nested to form a hierarchy. Sites which belong to a child group are also considered to be members of all its parent groups.
Fields
Parent
The parent site group, if any.
Name
The site group's name. Must be unique to the parent group, if one is assigned.
Slug
A unique URL-friendly identifier. (This value can be used for filtering.)