A bill of lading does three jobs at once: it is a receipt for the goods, evidence of the contract of carriage and, when issued in negotiable form, a document of title that controls who can collect the cargo. Air freight uses an air waybill instead, which works as a receipt and contract but is not a document of title.
Operations teams care about it because its details, such as consignee, quantities, weights and marks, have to agree with the commercial invoice, the packing list and the purchase order. A mismatch can hold a shipment at the port or delay payment under a letter of credit, which is why many teams check these documents field by field before they are released.