EDI (electronic data interchange)
EDI is the exchange of trade documents between the systems of two companies in a format agreed in advance: orders, dispatch advices, invoices. The document leaves one side's system and enters the other's as data ready to process, with no email, no PDF and no re-keying.
In a Polish wholesale business EDI usually appears because a retail chain or a large buyer makes it a condition of trading. Orders then arrive as messages, and the dispatch confirmation and the invoice have to come back through the same channel, within the deadline written into the contract.
Technically a supplier has two routes. Either it connects to an EDI operator that translates the messages and maintains the link with the buyer (in Poland these include Comarch EDI, Edison and Infinite), or it exchanges files directly over AS2 or SFTP where the buyer allows it. The message format is usually EDIFACT, sometimes an XML layout imposed by the buyer.
The work is not in the connection but in the data mapping. Internal item codes have to be matched to GTIN numbers, delivery points to GLN numbers, and units of measure and case packs set up the way the buyer reads them. A mismatch in any of these ends in a rejected message or a chargeback note.
You can tell the topic applies to you when someone copies chain orders from the buyer's portal into the ERP, the dispatch advice is built in a spreadsheet, and you learn about a broken message from a complaint. EDI that works shows a rejection the same day the message went out.