Dashes are punctuation marks used to create emphasis, indicate a break in thought, or set off information within a sentence. The most common types are the em dash (—) and the en dash (–). The em dash is often used in place of commas, parentheses, or colons to add clarity or drama to a sentence, while the en dash typically connects ranges of numbers or dates, such as 2010–2020. Dashes can enhance writing by providing a pause or interruption, allowing for a more conversational tone. They are versatile and can replace other punctuation marks, making them useful for writers looking to vary their style. However, overusing dashes can lead to confusion, so it's important to use them judiciously.