Most uses of punctuation are intended to express some type of meaning, regardless of the setting in which the punctuation is used. In written language, for example, punctuation is typically used to expand upon the meaning of what is said in words often by ending a sentence or expressing emotion. Punctuation can also be used in mathematical notations, often with different meanings than in written language, though such meanings have begun to expand from the mathematical uses into written language. There are also some uses of punctuation outside of common grammar or mathematics, including notation for chess and computer programming.
Regardless of which punctuation marks are used and the setting in which they are used, many uses of punctuation have some attributes in common. Punctuation is typically used to express meaning or expand upon what is around it in some symbolic way, allowing text to go beyond what is presented at a surface level. In written language, for example, punctuation is typically used to present information about what is expressed in words. A period allows readers to understand when an idea comes to a conclusion as the sentence ends, commas and semicolons can be used to break up complex ideas, and question marks and exclamation points allow a reader to better understand the purpose of a writer’s words.
There are also uses of punctuation outside of language, especially in mathematics. Beyond simple notations such as plus and minus signs, there are also other punctuation marks that can have meaning in math. The > and < signs, for example, mean “greater than” and “less than” in math, while brackets and parentheses are used to separate different parts of an equation or problem. These uses of punctuation in mathematics have begun to spill over into written language in some informal contexts. Someone might use a phrase like “me > you” to say that he or she is better than someone else.
A number of uses of punctuation have also gone beyond standard written language or altered written language. In chess notation, for example, exclamation points and question marks are often used to indicate moves that are quite good or moves of questionable effectiveness. Computer programming uses numerous punctuation marks to indicate various concepts within a certain language or syntax, often for separating parts of code or beginning and ending a command line. The rise of text and instant messaging has also expanded the uses of punctuation in written language through the development of emoticons and other symbols to quickly express ideas through non-verbal means.