[简答题]Documentary collection is a means of payment ensuring that the goods are only handed over to the buyer when the amount shown on a bill of exchange is paid or when the customer accepts the bill as a contract to pay by a specified date.The exporter sends the bill of exchange and the shipping documents to his bank, which forwards them to a bank in the customer* s country. This bank, or the exporter s agents in the country concerned, takes the documents to the customer. If it is a sight bill, the customer pays the amount directly. If it is a time bill，he signs the bill，which means he has “accepted” it for payment within a certain specified time. In return for either payment or acceptance of payment, the customer is handed the shipping documents which give title to the goods.