I am new to ABAP debugging and often face issues where my program gives an error, returns incorrect data, or does not enter the expected condition.

I know that breakpoints can be used, but I want to understand the complete debugging process in a simple and practical way.

For example, I want to know how to find why an internal table is empty, why a SELECT statement is not returning data, why an IF condition is not working, or why sy-subrc has an unexpected value.

Please help with the following points:

• How can we start debugging an ABAP report, function module, class method, BAdI, user exit, or enhancement?
• What is the difference between session breakpoint and external breakpoint?
• When should we use a breakpoint, watchpoint, or conditional breakpoint?
• How can we debug a background job, RFC call, update task, IDoc, or Web Dynpro application?
• How do we check variable values, internal tables, structures, field symbols, and references in the ABAP debugger?
• How can we identify why a SELECT statement returns no records?
• How can we use sy-subrc correctly while debugging?
• How can we skip code, change variable values temporarily, or move the execution pointer during debugging?
• What are the most useful debugger shortcuts and tips for beginners?
• What are common ABAP debugging mistakes and how can they be avoided?

A simple step-by-step explanation with real examples, screenshots, and common troubleshooting scenarios would be very helpful.