In a NetWeaver environment, we always need to remember the differences between the application server layer and the presentation layer. The application server layer is, as you may already know, a runtime environment for ABAP code. At a lower technical level, the application server is a remote server on which the NetWeaver platform is installed. The presentation layer instead can be understood as your local PC.
This difference is very important in the case of reading and writing files because SAP provides separate sets of tools in each case—one for processing files on the presentation layer and a second for processing files on the application server. Both are commonly used in SAP projects and will be fully covered in this chapter.
