The consignor, in a contract of carriage, is the person sending a shipment to be delivered whether by land, sea or air. Some carriers, such as national postal entities, use the term "sender" or "shipper" but in the event of a legal dispute the proper and technical term "consignor" will generally be used.
If Sender sends a widget to Receiver via a delivery service, Sender is the consignor and Receiver is the consignee.