Here you specify the formats in which the data has to be transferred in the function module interface.
BAPIs are not end user interfaces, they are programming interfaces that can be used in diverse application areas, for instance, to connect non-SAP systems and PC products to the R/3 System.
Fields in BAPI parameters must be presented in a neutral form used in the database and not in a form formatted in the BAPI interface.
SAP-specific data formats must be converted into the data format required externally. This applies to, for example:
To do this you can generate function modules that can map the relevant data to each other and perform the conversion. For further information about these exceptions seeInternal and External Data Formats.