HYPHEN
Hyphens are used to break single words into parts, or to join ordinarily separate words into single words.
Example: Son-of-a-bitch.
EN-DASH
The EN dash is commonly used to indicate a closed range of values.
Example: 2:00–6:00 pm. For ages 10–16 years of age.
EM-DASH
EM Dashes are used to indicate a break in thought or sentence structure, to introduce a phrase added for emphasis, definition, or explanation, or to separate two clauses and avoid a comma splice.
Example: Clearly, I can do it—as long as I’m in range. I know what I’m doing—been doing it for years.
Crime Fiction: Hardboiled Detective 