(Electronic Data Interchange) The computer-to-computer exchange of business documents or business information in a structured or standard format. An EDI message contains a string of data elements, each of which represents a singular fact, such as a price, product model number, and so forth, separated by a delimiter. The entire string is called a data segment. One or more data segments framed by a header and trailer form a transaction set, which is the EDI unit of transmission. A transaction set often consists of what would usually be contained in a typical business document or form. The parties who exchange EDI transmissions are referred to as trading partners.