I am confused a little bit here , I Know it is really very simple question , but I am not getting it properly.
What Actually Debugging process do ? On Google it says \"
In particular, a "debugger" is a software tool that allows you launch another program (the program that is being debugged), and to observe it while it is running. You can, for example, set "breakpoints" which will cause the program to stop at a particular point, and you can then observe the values in CPU registers, memory, and so forth.
You can't fix bugs in the debugger, but you can find them.
Having said all that, I almost never use these tools. I find that "printf debugging" (as Nilesh put it ...) is much more useful.