SAP R/3 Architecture

The SAP System has a three-tier client/server architecture.In SAP Application server all the data is stored in a database and the data is always processed by the application layer. The connection between the different layers are connected with network.Depending on the requirement Application layer and Database layer can be hosted on single single or disturbed system.


R/3 three tier architecture stands for Real time data processing in three tier architecture.

Presentation Layer
It layer creates an interface between the Application Server and End User. SAP systems can be connected in two ways:
- SAP GUI
- Browser

Application Layer
It consist of Primary Application Server(PAS) and ABAP Central Services (ASCS) or SCS in case of JAVA.  PAS consists of Dispatcher, Watchdog and Gateways Service where as ASCS or SCS consists
Message Server, Enqeue Service.

Database Layer
It consist the RDBMS which stores the data of SAP system.SAP is compatible with several databases i.e Oracle, Sybase, MaxDB, SQL Server, HANA.