To effectively use interactive lists for interactive reporting, it is not sufficient for the program to react to events triggered by user actions on the output list. It must also be possible to interpret the lines selected by the user and their contents.
To do this, you use information that the interactive lists pass to the program. ABAP provides two ways of passing data:
Automatic data transfer using system fields.
You use automatic data transfer mainly for auxiliary data that you need to better localize user actions.
Program-controlled data transfer using ABAP statements.
You use program-controlled data transfer to transfer the contents of individual output fields into the processing blocks of the interactive events and to continue processing with these values.