The shortest dash; should only be used between words or to break syllables at the end of a line of type.

Discretionary Hyphens

Becomes invisible unless needed. A discretionary hyphen is manually inserted where you want a word to break if and when that word appears at the end of a line. If the text reflows and the need for hyphenation is eliminated, the hyphen disappears. InDesign: Command (Mac) or Control (PC) + shift + hyphen. QuarkXPress: Command (Mac) or Control (PC) + hyphen.

En dash

The width of an en dash is one half the point size of the type i.e. 10 point type would use a 5 point en dash. Used to indicated a range in numeric values. On a PC hold down the ALT key and type 0150. On a Mac hold down the OPTION key while typing a hyphen.

Em dash

The width of an em dash is the same point size of the type i.e. 10 point type would use a 10 point em dash. Used to set off phrases in place of parentheses. On a PC hold down the ALT key and type 0151. On a MAC hold down the SHIFT and OPTION keys while typing a hyphen.