The IOU and IOU are not better. Both IOU and IOU have legal effect, but they are quite different.
 1、 The debit note proves the borrowing relationship, and the borrowing is mainly caused by borrowing; The IOU proves the debt relationship, and the debt may be caused by sales, leasing, interest and other reasons.
 2、 There are differences in the limitation of action. If the date of repayment is agreed upon in the IOU and IOU, the limitation of action shall be calculated from the expiration date; In the absence of such agreement, the limitation of action for the IOU shall be calculated from the date when the creditor knows or should know that the rights and interests are damaged, while the IOU shall be calculated from the date when the arrears are formed.
 3、 The reason for the formation of the IOU is the specific borrowing fact. There are many reasons for the formation of IOUs, which can be based on a variety of facts, such as the arrears arising from sales, labor services, enterprise contracting, and damages.
 [Legal Basis]
 In Article 667 of the Civil Code, a loan contract is a contract whereby the borrower borrows a loan from the lender, repays the loan and pays the interest when due.