An exception is a situation during ABAP program execution in which normal program continuation does not appear to be desirable. Exceptions can be triggered both implicitly in the ABAP runtime environment and explicitly in the ABAP program. For example, division by zero results in an exception in the ABAP runtime environment. You can detect this situation with a query in the ABAP program and trigger an exception there yourself.

There are exceptions that can be handled and those that cannot:

• Exceptions that can be handled occur in error situations in the runtime environment or in an ABAP program in which the program execution can be continued by handling an exception in the ABAP program without the system reaching a critical state. If such an exception is not handled, a runtime error occurs.
• Exceptions that cannot be handled are critical error situations in the runtime environment in which it is not possible to handle the error with ABAP means, always resulting in a runtime error.

With Release 6.10, exceptions and their handling are based on exception classes. This new concept includes and enhances the functions of the previous concepts.