The International Bank Account Number, or IBAN, is a standardized format for identifying bank accounts across countries. It helps facilitate international transactions by providing a unique identifier for each account, which includes a country code, check digits, and the bank and account number. IBANs are used primarily in Europe and other regions that have adopted this system to streamline cross-border payments. By using an IBAN, banks can reduce errors and ensure that funds are transferred accurately and efficiently between different financial institutions.