Sometimes large orders of multiple items will be shipped in more than one package. In these cases, the tracking number you receive will be linked with the tracking of the other parcel(s).
Most often, all pieces in a shipment will be delivered at the same time. However, occasionally, parcels can get separated, and items may be delivered later than other pieces of the order. You will want to check your tracking number on the courier's website tracking to see all the pieces in a shipment, and to track any remaining pieces.