In typography, symbols used to break up or end sentences, such as the period (.), comma (,), question mark (?), exclamation point (!), apostrophe ('), and quotation marks ("", ). There is also the colon (:), semicolon (;), and hyphen(-).
Aldus Manutius, the great Venetian printer, was one of the first to use punctuation marks to break up text. Prior to the advent of printing, punctuation was rarely and inconsistently used, and served primarily as cues for the proper reading of text aloud in church. The period was used as a full stop at the end of a sentence, while the solidus was used as a comma, to indicate a brief pause in the reading, and was introduced into English printing in 1521, although it was used in Venetian printing before 1500.
The question mark was derived from the Latin word quaestio (meaning "for what"), and came to England in 1521. The exclamation mark (also called a screamer or a bang) came from the Latin word io (meaning "joy") and dates from much later. The semicolon didn't appear in England until 1569, but only became widely used after 1580. The open single quote (') and the close single quote (') were used interchangeably in such abbreviations as th for "the", and t'is (for "'tis") and were common in the Elizabethan period.
In display typography, the word space placed after a comma or an abbreviation period should be reduced slightly to compensate for the excess space created optically by the punctuation mark. A variety of word spacing called French spacing places an additional space between sentences, and was common in printed books through the nineteenth century. In typewriting, this is accomplished by means of an additional word space; in typesetting, a thin space can be used rather than a second word space to achieve French spacing, for those who desire it.
Modern computerized desktop publishing programs are creating another stylistic punctuation problem involving quotation marks. Most word processing programs and some page makeup programs use the single/double quote key to set inch marks (") and foot marks ('). These are typographically unacceptable as quotation marks, and often option or shift-option combinations are needed to set smart quotes (also called curly quotes).