Using ABAP Help 

The help function in the ABAP Editor allows you to display information about ABAP syntax, semantics, and the individual ABAP keywords.

Starting the Help

You can start the help as follows:

By selecting the bottom node in transaction ABAPDOCU

You can display help for the following areas:

 

You can also create an offline version of the ABAP keyword documentation on your frontend.
The entire keyword documentation (including navigation structure) will be downloaded in HTML format into a directory on your PC. This takes between 10 and 20 minutes. You can then open the file BASIC.HTM. The offline documentation only supports links to other topics that were also included in the download, but it can be used independently of the R/3 System.