Electronic Data Interchange. EDI was the forerunner to the Internet and acted as an electronic means by which trading partners could share information and transact with each other. In some instances, the systems were so set up that when an item reached below a specified quantity of stock, automatic purchase orders were released from one company to the next via EDI. The receiving company would ship the item and inform via EDI that the items were shipped. While EDI is quite old technology, there are still many firms that rely on EDI and are unwilling to change their technology platform.