The tender is prepared by the tendering unit or the entrusted design unit, and provides the bidder with the documents of the main technology, quality and time limit for the project.

Bidding documents are legally binding and enforceable bidding behavior standard documents that all purchasers should abide by when bidding. The tender is also the basis for the bidder to prepare the tender, and the bidder must make a substantive response to the contents of the tender, otherwise it will be judged as invalid (treated as invalid tender). Tender is also the most important basis for bid evaluation. Generally, there is at least one original and two or more copies of the tender.