The Free On-line Dictionary of Computing (30 December 2018):

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 VDUs.  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)