Debugging is the process of detecting errors or bugs while your program is running. If you have successfully fixed all the compilation and syntax errors with the help of the Error List window, the next step is finding logic errors and exceptions while the program is running.
Visual Studio offers useful tools for debugging. With these tools, you can pause the execution of the program at certain points and monitor the values of the variables used by your program. You can do a step by step, line by line execution of code and you can go inside method calls. You can check details about the exception and you will be given tips on how to fix them.