The em dash, sometimes referred to as simply a dash, is one of the most versatile punctuation marks we have in the English language. It looks like this:
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You can enter it by typing ALT + 0151 (hold down ALT, type 0151, and release); many word processors will insert it if you type two hypens back [...]

The en dash replaces the word to in numerical phrases

Everyone knows how to use hyphens, right? No. In fact, there’s not even a good grammar rule about their usage, much less a general consensus.