This documentation describes the classic ABAP user interface technologies that are supported by function groups, module pools, and executable programs.
A general, classic screen is a component of an ABAP program. It is created with the Screen Painter tool in the ABAP Workbench and called with either a transaction code for the CALL SCREEN statement. Every time a screen is called, a screen sequence is started.
A selection screen is a special type of classic screen that is defined with the ABAP statements PARAMETERS, SELECT-OPTIONS and SELECTION-SCREEN rather than being created in the Screen Painter. Selection screens are called either implicitly when an executable program is started or explicitly using the CALL SELECTION-SCREEN statement.
Classic lists are used to output data in a structured and formatted manner. The formatted data is stored in a list buffer by special ABAP statements ( WRITE, FORMAT, and so on) and displayed on a special system screen. Classic lists are called either automatically when an executable program is run or with the LEAVE TO LIST-PROCESSING statement.
Messages are texts that can be displayed with the MESSAGE statement while a screen is being processed. Messages are always displayed in the current logon language, which cannot be changed during a user session. Messages are organized in message classes and message numbers and can be edited with the message maintenance transaction (SE91). When a message is displayed with MESSAGE, it is classified with a message type that defines how it appears.
When creating user interfaces for new applications, you should use Web Dynpro ABAP instead of the classic UI technologies. If you still want to use classic screens, you should use the SAP List Viewer (ALV) instead of classic lists.