An exception is an event that occurs during the execution of a program, and requires the execution of code outside the normal flow of control. There are two kinds of exceptions: hardware exceptions and software exceptions. Hardware exceptions are initiated by the CPU. They can result from the execution of certain instruction sequences, such as division by zero or an attempt to access an invalid memory address. Software exceptions are initiated explicitly by applications or the operating system. For example, the system can detect when an invalid parameter value is specified.
C++ Programmer at Microsoft