Walk straight through any retail brick and mortar establishment, to the back of the building, and on a door you will find a sign that reads, "Employees Only". Behind that sign, beyond the sight of customers, there is much activity that goes on. Deliveries are being accepted, seasonal merchandise lays in wait for the return of the holidays and customer layaway purchases are shelved. Some antique stores also use this private area to do repairs and restorations, or to hold merchandise as unavailable until the proprietor has had time to examine, identify and price an item destined for the sales floor.
The virtual "Backroom" feature in your shop was created to function just like such an "Employees Only" storage and workroom. It is a private, "Shop Owner Only" work area. The items listed there are not made publicly available, nor can they be purchased.
Items are automatically moved to the Backroom as you request, when a certain number of shoppers have viewed the item or after the item has been listed in your shop a certain amount of time. The shop owner specifies this information when adding or modifying an item.