When you program with ABAP on the application server, you profit from a range of services, which in other languages would have to be programmed manually. Get a basic understanding of the architecture of the SAP NetWeaver Application Server ABAP and its strengths such as development on a central server or integrated software logistics (SAP Change and Transport system). And, of course, learn about the basic tools of the ABAP development environment and ABAP itself as a language.
SAP NW Application Server
Learning Material for Beginners
ABAP in Eclipse: ABAP Development Tools for SAP NetWeaver