The ledger is a detailed record sheet. It does not belong to the accounting system in accounting. It is not the account book recorded during accounting. It is an auxiliary account book set up by the enterprise in order to strengthen the management of certain aspects and understand certain aspects of information in more detail. It is a special invoice ledger. It is a detailed registration of purchases, sales and deposits based on the special invoices purchased by the company. To comprehensively reflect the information used for the purchase of enterprise-specific invoices.