A screen is an object of the repository, and always exists as a component of an ABAP program. It consists of a screen layout with its screen elements, and the flow logic. Screen fields are assigned to the screen elements.
The flow logic contains processing blocks for events that are triggered before a screen is sent, and after user action on the displayed screen. Screens are edited using the Screen Painter tool. Screens, together with the new features of the SAP NetWeaver Application Server, therefore form the basis of user dialogs in an ABAP system.
Screen flow and screen sequences
Statements of the screen flow logic
ABAP statements for screens