The exchange of specific business documents with your EDI trading partners is known as EDI transactions or EDI messages. These documents strictly adhere to EDI standards like EDIFACT here in the UK and internationally and X12 EDI, which is used in the US.
An EDI transaction encompasses a wide range of documents, including invoices, purchase orders, and health insurance benefits requests. Although there are over 10,000 different EDI messages available, most organizations typically exchange the most common ones. The three most used messages are Order, Invoice, and Despatch Advice (also known as Advanced Ship Notice).