ABAP Language
ABAP stands for Advanced Business Application Programming. It is a programming language developed by SAP. SAP is a German company that develops ERP (Enterprise Resource Planning System) systems. These systems are used by companies to track all information related to the business integrating finance, sales, pruchases, and materials management. ABAP/4 is the programming language used for the thousand tiny embedded programs called transactions that make up the application. The /4 means it is a fourth generation language.
ABAP is an programming language which runs in the ABAP virtual machine.An ABAP Compiler is a compiler, which creates a BYTE CODE also known as INTERIM CODE whenever an ABAP program is generated from the source code. This BYTE CODE or INTERIM CODE is stored in the database system being used by the SAP System.
A BYTE CODE is a collection of Statemets and are connected to C functions.Whenever the program is generated, the byte code is loaded into a program memory area (PXA) that is used to manage the generated byte code. The loaded byte code is finally interpreted by ABAP runtime environment.
All ABAP programs reside inside the SAP database. They are not stored in separate external files like Java or C++ programs. In the database all ABAP code exists in two forms: source code, which can be viewed and edited with the ABAP Workbench tools, and generated code, a binary representation somewhat comparable with Java bytecode. ABAP programs execute under the control of the runtime system, which is part of the SAP kernel. The runtime system is responsible for processing ABAP statements, controlling the flow logic of screens and responding to events (such as a user clicking on a screen button). A key component of the ABAP runtime system is the Database Interface, which turns database-independent ABAP statements (“Open SQL”) into statements understood by the underlying DBMS (“Native SQL”). The database interface handles all the communication with the relational database on behalf of ABAP programs; it also contains extra features such as buffering of frequently accessed data in the local memory of the application server.
Please find below links for the detail information about ABAP language:
http://help.sap.com/saphelp_nw70/helpdata/EN/43/41341147041806e10000000a1553f6/frameset.htm
This link is about a comprehensive document of SAP netweaver platform.
http://help.sap.com/saphelp_nw70/helpdata/EN/e7/c7af3fda5a3c17e10000000a114084/frameset.htm
