Quoting

String	Meaning
'...'	Literal character string. Only do history substitutions.
"..."	Single word. Typically used if there are embedded blanks or wildcard characters you want treated as ordinary. Has no effect on command or variable substitutions: they’re still done.
`...`	Command substitution. Evaluate the string as a separate command and substitute its output back onto the command line. Newlines are turned into spaces and ANSI escape sequences (for highlighting, etc.) are filtered out.
^	Quote just the next character. Use to remove any special meaning from the next character, to specify a character by its binary value or to specify one following non-printable characters. If the NewLine character at the end of a line is quoted this way, it’s treated as ordinary white space. (You can choose a different escape character by changing the escapesym variable.) Escape Sequences String Meaning ^a Audible alert (bell) ^b Backspace ^f Form Feed ^n New Line ^r Carriage Return ^t Tab ^v Vertical Tab ^^ Single escapesym character