There are three dashes in English language typography.
The hyphen is used to split words at ends of lines or conjoin words: a top-heavy pistol or a late-feeling arrival.
The en dash, so called because it was originally the width of a capitan N, is used to indicate ranges of dates or numbers: three–four days, 11:30–noon. I'd wager not one typographer in twenty has ever so much as heard of the en dash.
The em dash, so called because it was originally the width of a capital M, is used to break or disrupt a statement: the em dash—sometimes used in place of parentheses—is frequently over-used these days.
Ellipses consist of three periods, and are used to indicate something has been left out or incomplete: we went to the gun shop, but...