Source : Free On-Line Dictionary of Computing

fatal exception
     
         A program execution error
        which is trapped by the {operating system} and which results
        in abrupt termination of the program.
     
        It may be possible for the program to catch some such errors,
        e.g. a {floating point} {underflow}; others, such as an
        invalid memory access (an attempt to write to read-only memory
        or an attempt to read memory outside of the program's {address
        space}), may always cause control to pass to the operating
        system without allowing the program an opportunity to handle
        the error.  The details depend on the language's {run-time
        system} and the operating system.
     
        See also: {fatal error}.
     
        (1997-08-03)