Debugging is the way to find the root cause of certain SAP transactional behavior (e.g., finding a reason why a certain value in a field was updated or determining why users receive an error, warning, or abnormal termination message during the processing of a transaction). Debugging is necessary if the root cause cannot be determined from functional methods such as checking customizing or master data.
Since ABAP is the backbone of SAP, at one point or another, every member of a functional team must have had to deal with SAP development technicalities behind the business functionality. This need for technical details can occur during various phases, such as writing functional specifications or analyzing a production environment issues.