Cargo insurance protects the value of the load itself. If freight is damaged, stolen, or destroyed during transport, this coverage is what pays out on the resulting claim — as opposed to liability insurance, which covers harm the truck causes to others.
Shippers and brokers often require a carrier to carry a minimum amount of cargo coverage before handing over a load, and they’ll ask for a certificate of insurance as proof. It’s a basic condition of being trusted with valuable freight.