Next, I got an error message. An "error message" is a short message that
appears on your computer screen when something has gone wrong, or when the
computer is no longer working properly. "Error" means mistake; in this case,
there's some problem with the computer. Sometimes error messages say things
like "A fatal (or deadly) error has occurred," and then when you click "OK" the
program shuts down and you lose whatever document you were working on. "To
shut down" means to close down, to no longer be operating on your computer.