Today, due to the expansion of economic and contractual relations, individuals and legal entities use various methods to conclude their intended transactions and choose the other party, including holding auctions, auctions and tenders. In this method, people express their terms and conditions of trading with public announcement and invite interested people and applicants to conclude a contract in the form of demand, which after reviewing these offers by the organizer the best and most appropriate Accept them until the final contract is concluded. Therefore, while paying attention to these concepts, it is necessary to explain the role of their nature in contract law, because considering their application in contracts, especially government contracts, recognizing this category is of great importance, which also has important practical effects.