1 A character that changes the meaning of a character or characters immediately following. It is like a temporary shift character. The ASCII characters ESC and DLE are used in this way. Graphic characters (See character set) are also used as escape characters in particular contexts.
2 A character that causes the character or characters immediately following to be read by an application but not interpreted by the application. This occurs, for example, with text-formatting applications, where certain characters that usually indicate formatting directives may, in some cases, constitute part of the formatted output.