Eli5: how were things like old books digitized for the internet? Did someone scan each page? Did they just re-type it word for word?

Question

I was thinking about public domain books and it got me wondering.

In: Technology

Answer 1

Yep, scanning. There are specialized machines [like this](https://www.youtube.com/watch?v=cmhIJOqepVU) that can scan books pretty fast. Errors were corrected by tools such as reCAPTCHA that we’ve seen on just about every login page on the web.