ABAP
As in other programming languages, an ABAP program is either an executable unit or a library, which provides reusable code to other programs and is not independently executable.
ABAP distinguishes two types of executable programs:
Reports follow a relatively simple programming model whereby a user optionally enters a set of parameters (e.g., a selection over a subSET of data) and the program then uses the input parameters to produce a report in the form of an interactive list. The term “report” can be somewhat misleading in that reports can also be designed to modify data; the reason why these programs are called reports is the “list-oriented” nature of the output they produce.
Module pools define more complex patterns of user interaction using a collection of screens. The term “screen” refers to the actual, physical image that the user sees. Each screen also has a “flow logic”, which refers to the ABAP code implicitly invoked by the screens, which is divided into a “PBO” (Process Before Output) and “PAI” (Process After Input) section. In SAP documentation the term “dynpro” (dynamic program) refers to the combination of the screen and its flow logic.
The non-executable program types are:
- INCLUDE modules
- Subroutine pools
- Function groups
- Object classes
- Interfaces
- Type pools
