ABAP - Object Services 
ABAP - Object Services
Purpose
Object Services provide global services, which ABAP Objects language elements cannot provide themselves, to applications written in ABAP Objects.
Features
These Object Services include:
The exception class hierarchy lets you handle exceptions appropriately. (See
Exception Handling).Architecture
Object Services represent a software layer, programmed in ABAP Objects, between the ABAP application program and the ABAP runtime environment. This layer helps you manage objects in the application program.
Application objects are managed using Object Services objects known as class actors or agents. There is exactly one class actor for each application class, used to manage the objects of that application class. As well as externally visible services, Object Services also includes services (in some cases used internally), such as an Undo Service and a general System Service.
