What does it do?

I'm not sure what this module is for. I am looking for a way to group domains in a way that they are treated as one, i.e. they have the same theme, settings, permissions, etc. But it seems this module only lets you group domains for no further purpose than displaying what has been grouped. Is this correct? I don't understand the mapping feature either. Mapping domains to a group doesn't seem to have any effect.