System Exception Vs Application Exception

• System Exception and Application Exception are both derived from Exception.SystemException. It is the predefined base class for exceptions that originate from the System namespace.ApplicationException.
  
• System namespace.ApplicationException is the class intended as a base for any application.
  
• If we want to define exceptions for our application, then we have to derive exception class from ApplicationException
  
• Syntax:
  

  public class CustomException : ApplicationException .