The Dash.

They are similar to to a hyphens and minus signs.

The En dash.

The dash most common versions of the dash are the en dash () and the em dash (). An en dash, roughly the width of an n, is a little longer than a hyphen. It is used for periods of time when you might otherwise use to.

The Em dash.

An em dash is the width of an m Use an em dash sparingly in formal writing. In informal writing, em dashes may replace commas, semicolons, colons, and parentheses to indicate added emphasis, an interruption, or an abrupt change of thought.