Hyphen (-) — the one on your keyboard. For compound words like “well-known.”
En dash (–) — medium length, for ranges like 2020–2024. Mac: Option + hyphen. Windows: Alt + 0150.
Em dash (—) — the long one, for breaks in thought. Mac: Option + Shift + hyphen. Windows: Alt + 0151.
And now I also understand why having plenty of actual em-dashes (not double hyphens) is an “AI tell”.
En dash is compose --.
You can type other fun things like section symbol (compose So) and fractions like ⅐ with compose 17, degree symbol (compose oo) etc.
https://itsfoss.com/compose-key-gnome-linux/
On phones you merely long press hyphen to get the longer dash options.
That said I always use -- myself. I don't think about pressing some keyboard combo to emphasise a point.