There are three main horizontal strokes, not counting an underscore, used in English: the em dash (—), the en dash (–), and the hyphen (-).
Em dashes are the longest at about the width of a capital M. They’re used to break up thoughts in a sentence, much like a semicolon: “He ran—but not fast enough.”
En dashes are the second shortest, and you’d have to use a code (or copy/paste) to use one. They’re used to separate numbers in a range like 7–9. Sometimes people use spaced en dashes (en dashes with spaces on either side) in place of em dashes. But I don’t agree with that practice.
Hyphens are the shortest, and they’re on your keyboard. Hyphens are used to hyphenate words at the ends of lines or to connect compound words like sheep-stealing.