Difference between Pre-shipment & post-shipment documents in case of export as under.
Pre-shipment Documents which are prepared before shipment i.e. Export order, Invoice, P/list, Product catalogue/ Literature/Drawings etc. The declaration given to customs

Post- Shipment Documents which are prepared after shipment means sailing of the cargo i.e. Bill of lading, Certificate of Origin, legalise documents etc. Insurance certificate in case of terms of delivery CIF or C&I

Documents is received by the overseas party in export consignment i.e. Invoice , P/list, Product catalogue/ Literature/Drawings etc.; Bill of lading , Certificate of Origin, legalise documents etc. Insurance certificate in case of terms of delivery CIF or C&I.