Resource Reservation Template Problem

Hi,

I am using a resource reservation default template of notes.

When user creates a new resource, Some owner restrictions comes(none, owner only,specific people…) and some additional fields(Additional Approver, Super User) comes.

Can anyone please assist me, what is the impact of these additional fields(Additional approver, super user) while reserving a resource?? What exactly these additional fields do??

Thanks

Suchita