Why is the ninth month called September?
in economics, the exchange of physically intangible items between countries. Invisible trade can be distinguished from visible trade, which involves the export, import, and reexport of physically tangible goods. Basic categories of invisible trade include services (receipts and payments arising from activities such as customer service or shipping); income from foreign investment in the form of interest, profits, and dividends; private or government transfers of monies from one country to another; and intellectual property and patents. (See also intellectual-property law.