Report item is nothing but a query item when it is drag and drop into the work area.
Example in Go sales and retailers package-> Product (is a query subject) and-> Product line is( a query item)->when PL is dropped into the work area then its a report item.
Example in Go sales and retailers package-> Product (is a query subject) and-> Product line is( a query item)->when PL is dropped into the work area then its a report item.