From a modern point of view, SAP's architecture feels pretty alien. In a way you're right, and it's a massive amount of forms on top of a database, plus stagger

From a modern point of view, SAP's architecture feels pretty alien. In a way you're right, and it's a massive amount of forms on top of a database, plus staggering amounts of business logic. But as it was born before the web, it does not render to HTML, but to it's own display system. Most parts are written in ABAP, an interpreted language, and the source code is stored in the database. A quite usable IDE and a debugger are included. The source code is there, so you can read it and explore how things happen. There's a database abstraction layer, which works around some limitations of the underlying databases. What SAP sees as a table might be a set of tables in the database. It's not an unpleasant system to work with.