Source : Free On-Line Dictionary of Computing

escape sequence
     
         (Or "escape code") A series of characters starting
        with the {escape} character (ASCII 27).  Escape sequences are
        often used to control display devices such as {VDU}s.  An
        escape sequence might change the colour of subsequent text,
        reassign keys on the keyboard, change printer settings or
        reposition the cursor.  The escape sequences of the {DEC}
        {vt100} {video terminal} have become a {de facto standard} for
        this purpose.
     
        The term is also used for any sequence of characters that
        temporarily suspends normal processing of a stream of
        characters to perform some special function.  For example, the
        {Hayes} {modem} uses the sequence "+++" to escape to command
        mode in which characters are interpreted as commands to the
        modem itself rather than as data to pass through.
     
        [Was the character named after this use or vice versa?]
     
        (1997-11-27)