escape sequence
also: escape character, control sequence
A special sequence of characters (usually starting with a backslash or escape character) that represents a non-printing or special character, or signals a command to interpret text in a specific way.
An escape sequence tells the shell, terminal, or application to interpret the following characters as having special meaning rather than their literal value. The most common escape character in Linux is the backslash (\), which modifies the character immediately following it.
Common examples include \n for newline, \t for tab, \\ for a literal backslash, and \' for a single quote. These are heavily used in strings, regular expressions, and command-line arguments.
For example, echo -e "Hello\nWorld" uses the escape sequence \n to print "Hello" and "World" on separate lines. Without the -e flag, the sequence would be printed literally.