one of the marks used to indicate the beginning and end of a quotation, in English usually shown as “ at the beginning and ” at the end, or, for a quotation within a quotation, of single marks of this kind, as “He said, ‘I will go.’ ” Frequently, especially in Great Britain, single marks are used instead of double, the latter being then used for a quotation within a quotation.
They are comma- and quotation mark- delimited files.
To show a quote within a quote, use the single quotation mark or apostrophe.
British Dictionary definitions for quotation mark
either of the punctuation marks used to begin or end a quotation, respectively “ and ” or ‘ and ’ in English printing and writing. When double marks are used, single marks indicate a quotation within a quotation, and vice versa Also called inverted comma