.NET interview questions: - What are system level exceptions and application level exceptions?
Exceptions that are thrown by .NET framework are called as system exceptions. These errors are non-recoverable or fatal errors like ArgumentOutOfRangeException, IndexOutOfRangeException, StackOverflowException etc.
Application exceptions are custom exceptions created for the application. Application exceptions are created by deriving from "ApplicationException" class as shown below. You can then create the object of the below exception and throw the same from the code and catch the same on the client side.
Also see following basic but important .NET interview questions video on debug directive