Parentheses are punctuation marks used in writing to enclose additional information or clarifications that are not essential to the main point. They help to provide extra context or examples without interrupting the flow of the sentence. For instance, you might see a sentence like, "The cat (which is very playful) jumped on the table." In mathematics, parentheses are also used to indicate the order of operations. They show which calculations should be performed first. For example, in the expression 2 + (3 × 4), the multiplication inside the parentheses is done before the addition, leading to a correct result of 14.