Thank you for your answer:
'I think a business object type like BUS1006 only telle you the type of the object (like business partner, opportunity, activity).You still need the business object like BTADMINH to read or save data without caring in which database table(s) the data is stored.'
But in transaction SWO1 i can see that the business object type BUS1006 (Business Partner) offers plenty of methods. I can even jump directly in the ABAP code of the method like "Change Business Partner" and see there which database tables are changed. Isn't that the same logic and knowledge the GenIL object BT has?
I am not deep into technology - from a satellite perspective i was just wondering why SAP innovated the complicated BOL/GenIL layer if there was already a concept for capsuled business objects in place. Yes - buffering is propably a plus but i am still wondering..maybe there is a simple reason but i do not see it because i am not deep enough in techology
