The Shortest Dash, The HyphenA hyphen is a short punctuation mark used to join words (such as well-read or jack-of-all-trades) and to separate syllables of a single word or the characters in a telephone number (123-555-0123).
The hyphen is the unshifted key between the 0 and +/= on a standard keyboard. Hyphens are usually shorter and thicker than the en dashes although it can vary by font and the difference may be hard to discern, depending on the font. - – —
The Short DashA little longer than a hyphen, the en dash is roughly equivalent to the width of the lowercase n in the typeface in which it is set. En dashes (–) are primarily for showing duration or range as in 9:00–5:00 or 112–600 or March 15–31. Informally, a hyphen often stands in for a proper en dash.
Create en dashes with Option-hyphen (Mac) or ALT 0150 (Windows) — hold down the ALT key and type 0150 on the numeric keypad. Create en dashes in HTML with & #0150; (ampersand-no space, pound sign 0150 semi-colon). Or, use the Unicode numeric entity of & #8211; (no spaces).
The Long DashFrequently seen written as a pair of hyphens, the em dash is a little longer than an en dash — roughly equivalent to the width of the lowercase m in the typeface in which it is set. Similar to a parenthetical phrase (like this) the em dash sets apart clauses in a sentence or may be used to provide separation for emphasis.
Create em dashes with Shift-Option-hyphen (Mac) or ALT 0151 (Windows) — hold down the ALT key and type 0151 on the numeric keypad. Create em dashes in HTML with & #0151; (ampersand-no space, pound sign 0151 semi-colon). Or, use the Unicode numeric entity of & #8212; (no spaces).