What writing function do parentheses fulfill?

The use of parentheses in writing primarily serves to clarify or provide supplementary details. When information is placed within parentheses, it offers additional context or examples that can enhance the reader's understanding without disrupting the flow of the main text. This allows the writer to include extra information that may be relevant but not essential to the core message.

For instance, in a sentence discussing a specific topic, parentheses can be used to insert a brief explanation or a reference, enabling the reader to grasp the content more fully while allowing them to decide whether to engage with the supplementary information. This function is distinctly different from other writing functions such as indicating direct quotes or separating items within a sentence.