When you define selection criteria, selection tables of the same name are declared in the program. The selections that the user specifies on the selection screen are stored in the rows of these tables in a standardized format. So that the program must not explicitly process the structure of the selection tables and their contents, selection tables can be addressed as a whole in certain ABAP statements. In these statements, complex selections are analyzed in a selection table. The programmer does not have to deal with their logic.