Primary/Additional Usergroup

[Goomzee]

what is different between Primary Usergroup -- and Additional Usergroups? becouse i search Super Moderators from Primary usergroup it's say i have 1 Super Mod but when i search Additional Usergro then it's show
No Users Matched Your Query?

[Dismounted]

It's just that - primary - "the first". It also determines the "default" display usergroup.