In typography, the opening and closing punctuation marks—"" ' '—indicating verbal statements or defining or emphasizing certain words. Double quotes are normally used in American books, with single quotes being used within double quotes, as in "Doubles on the outside, 'singles' on the inside," although in Britain this is reversed. The single close quote is also an apostrophe.
Quotes (or "quotation marks") were originally only commas, placed in the outer margin, and first began to be used by Morel of Paris in 1557. A century later, they resembled the so-called French quotes (« ») which were placed in the center of the type body so that the same character could be used for either the open or closed position. English printers refused to use the French form and used inverted commas for the open position and the apostrophe for the closed. This resulted in non-symmetrical quotes.
In some cases, it is necessary to use a small space to separate quotes from certain letters, and between single and double quotes where they abut each other.
Usually the punctuation at the end of a quote negates the need for additional space at the close. For good display typography, sometimes it is best to use quotes one size smaller so they are not too overbearing.