A hyphen is a punctuation mark (-) used to connect words or parts of words. It often appears in compound words, such as mother-in-law or well-being, to clarify meaning and improve readability. Hyphens can also be used to join prefixes to proper nouns, like pre-Columbian. In addition to compound words, hyphens are used to indicate word breaks at the end of a line. This helps maintain the flow of text. However, hyphens should not be confused with dashes (–), which serve different purposes in writing, such as indicating a pause or range.