There are three types of dashes. You might wonder what the difference is between a hyphen, en dash and em dash.
The hyphen, or minus sign, is used to show a word is hyphenated.
The en dash ( – ) is so called because it is as wide as an uppercase N in whatever the current font happens to be. There are complicated rules on how to properly use the en dash, but in practice it’s rarely used. When it is used, it is most commonly used to indicate a range, such as “March–April.” You may have seen this dash because whenever you use a double dash ( -- ), WordPress automatically changes it to an en-dash. You can also hard-code it by inserting – into raw HTML.
The em dash ( — ) is so called because it is as wide as an uppercase M in whatever the current font is–a bit longer than the en dash. It’s what you would normally think of as a dash—used to separate parts of sentences. You can write a long dash in WordPress with three hyphens: ---. You can also use the code — in raw HTML.