This is for grammar geeks. "The muse gets all the press, but here’s a fact: Good writing involves obsessing over punctuation marks. It’s 1 a.m., you’ve got a 5,000-word piece due the next day, and for the last twenty minutes you’ve been deliberating about the use of a semicolon versus a period in a single sentence."
The author of this post (someone Schulz) went in search of remarkable examples of punctuation and chose 5 for our enjoyment. I learned what an em-dash is through Schulz and how to make your keyboard write it.
There is also an en-dash. An em-dash differs from an en-dash in that the em symbol is the with of a m and the en is the with of an n. Ha.
To form an em dash on most PCs, type the first word, then hold down the ALT key while typing 0151 on the numerical pad on the right side of your keyboard. Then type the second word. You may also form an em dash by typing the first word, hitting the hyphen key twice, and then typing the second word. Your program will turn the two hyphens into an em dash for you.
To form an en dash with most PCs, type the first number or word, then hold down the ALT key while typing 0150 on the numerical pad on the right side of your keyboard. Then type the second number or word.
Illinois–Missouri border en-dash
The coast is clear—run! em-dash.
Gotta love it.