Bill of lading (BOL)

A bill of lading (BOL) is the legal contract of carriage between the shipper and the carrier. It names what is being shipped, where it is going, and who is responsible for the freight in transit, and it doubles as the receipt the carrier signs at pickup. Freight operations reconcile deliveries, claims, and invoices against the BOL number. The advance ship notice (ASN) describes the same shipment for the receiver's systems ahead of arrival.

Full guide: advance ship notices covers how an ASN works and how it differs from the bill of lading.