The exports of Laos and other countries are calculated as the total amount of goods and services produced at home and sold abroad. Exports are often reported as percent of GDP so that we can evaluate their magnitude relative to the size of the economy.
If exports are about 15 percent or less of GDP the economy is considered relatively closed as only 15 percent of its products are sold internationally. That, for example, applies to the U.S. In contrast, many small European countries export over 40 percent of their production. They are considered more open to international trade.