IDES stands for “International Demonstration and Education System”. It was only a demo system with all applications in order to learn faster and implementation. 

SAP R/3 is a third generation system with highly integrated software modules that perform the business function based on multinational leading practice. The application, database and presentation servers are located at different system in R/3 system. Coming to the application layer of an R/3 System is made up of the application servers and the message server, it runs on application server, as well it communicates each other with presentation components, database using the message server. The complete data is stored in Centralized Server and that server is called as database server.

Abstract class is a class designed with implementation gaps for subclasses to fill in and is deliberately incomplete.