You might have tried to use the Print Screen key (PrtSc on some keyboards) to print the contents of your screen to a printer. If so, you might have discovered that this key works properly only when your screen is in text mode.
If your monitor is a CGA, EGA, or VGA display, the external command GRAPHICS enables you to use the Print Screen key to print graphics screens, also. When you execute GRAPHICS, a portion of the program remains memory-resident. When you next press Print Screen, all ASCII code characters that would otherwise print as text are converted to graphics before the information is sent to the printer.