Electronic Data Interchange (EDI)
Electronic Data Interchange (EDI) is the electronic interchange of business information using a standardized format; a process which allows one company to send information to another company electronically rather than with paper. Business entities conducting business electronically are called trading partners.
The data format was created in the late 70s. The data format is unambiguous (like XML), very compact (unlike XML) and humanly unreadable (also unlike XML). It was the best protocol at the time to transmit vast amounts of data over a 300 baud teletype modem.
There is a number of standards, including X12, EDIFACT, and ODETTE.
Part of the EDI standard is the definition of a number of standardized documents. I.e.: EDI-837 describes a Health Care Claim, which is still used between Claims Processors and Health Care Insurances.