Em Dash vs En Dash vs Hyphen

The em dash (—, U+2014), en dash (–, U+2013), and hyphen (-, U+002D) are three distinct punctuation marks that are frequently confused. The em dash is the longest of the three and is used to set off parenthetical phrases or mark an abrupt break in thought — like this — in place of parentheses or commas. The en dash, roughly the width of the letter N, is used for ranges (pages 10–20, June–August) and to connect compound adjectives where one element is itself two words. The hyphen is the shortest and is used for compound words (well-known), hyphenated names, and line breaks — it is the only one found directly on a standard keyboard. A common mistake is typing two hyphens (--) as a stand-in for an em dash; most word processors auto-correct this, but in code or plain-text contexts the proper Unicode character should be used.