I remember my elementary school librarian had some kind of networked computer a touch later, 90-92 timeframe. She tried to explain what email was to me and I still remember being super confused. Think she even showed me on screen my I still did not get it.

It’s very brave to admit when something confounds you.

Start here: https://en.wikipedia.org/wiki/Email

If that’s too much, think of the internet as a series of tubes, and email as a digital boomerang that returns with an out-of-office reply attached.