[jbri]

On an actual typewriter, backspace just moves the head one character backwards. It doesn't inherently erase anything

But if you do want to actually erase text, there still is a way - many typewriters had multiple ink ribbons. In addition to black, you might have red for indicating deficits in accounting, or for erasing text you'd have a white ribbon.

So "erasing" on a typewriter is basically just typing the same text over the top again, this time in white so it doesn't show against the paper.

[KC8ZKF]

Didn't work on your carbon copies, though. In my high school typing class, accuracy was preternaturally stressed.

[gchpaco]

Yup, in the working world it was not unusual for secretarial professionals to be expected to turn out a perfect page every time or redo it until it was perfect.

[officemonkey]

When I was younger, I once worked with a professional secretary. She could touch-type accurately like a speed demon, and she could take shorthand. This was in the days before corporate email, so everything was done using interoffice memos, and she was worth her weight in gold.

I wish I learned shorthand (such as teeline) while I still had the time/energy to learn it. I'm sure technology like Siri will put an end to that.