Classic debugger is the one used earlier for older versions. now there is a new one. These are user friendly when you point on an icon will give you the info or else you can click and check them functionality in a test program. These are user friendly.
if you go to utilities -> settings and the debugging tab you will see these two options. you can toggle between them and check the difference and the look and feel.
Debug Program scheduled Background
3 types update,normal and system debugging
check this for update debugging
If you set "Update Debbugging" you can debug the codes which works in update tusk.
SAP std often runs the routine (function or form) to update the database in update tusk mode, these routine start as soon as a commit work is done.
The commit is called at the end of the program, so you can't debug them by "normal debbugging" because it ends as soon as the program ends
All the database updates are performed by the update work processes by calling the functions/subroutines in update tasks.
These tasks are executed after a commit work is reached in the application. By default you cannot debug these functions.
TO debug these u need to explicitly activate update debugging.
for system debugging check the below link
For debugging tutorial:
If you set this option, the Debugger is also activated for system programs (programs with status S in their program attributes). When you save breakpoints, the System Debugging setting is also saved.
Update function modules do not run in the same user session as the program that is currently running in the ABAP Debugger. These function modules are therefore not included in debugging. Only if you select the Update Debugging option can you display and debug them after the COMMIT WORK.
Normal debugging is the one we do it by the normal dynamic break points or by /H or by using stattic break points.
You can switch to diffferent debuggin modes while processing.
In the source code we set the Break-point there by clicking the stop button, the system will stop there when you execute the program.
For watchpoints, we need to give some condition and when this condition is satisfied, program will stop
example : if you want to debug only
for matnr value 100 than set watch point
matnr = 100. when value reaches 100 than
program stops at that point.
check these documents as well
award points if it helps you.
here r some links for debugging...
Go through these threads for more information on debugging,
some more links .....
A PDF file to know knowledge about Debugging
Some more links:
Debug Background Programs: http://www.sapdevelopment.co.uk/tips/debug/debug_backjob.htm
If you need further info shoot me a test mail