How does countertrade work in international business?

"Countertrade International trade does not always involve cash. Today, countertrade is a fast-growing way to conduct international business. In countertrade, part or all of the payment for goods or services is in the form of other goods or services. Countertrade is a form of barter (swapping goods for goods), an age-old practice whose origins have been traced back to cave dwellers. The U.S. Commerce Department says that roughly 30 percent of all international trade involves countertrade. Each year, about 300,000 U.S. firms engage in some form of countertrade. U.S. companies, including General Electric, Pepsi, General Motors, and Boeing, barter billions of goods and services every year. Recently, the Malaysian government bought 20 diesel-powered locomotives from China and paid for them with palm oil."