I first encountered the term ‘beta reader’ while reading Harry Potter fanfiction online. From the author notes, I surmised that beta readers were the first people to read a story, and that they helped to polish them into finished pieces. I assumed that a beta reader was like an editor, but not paid.
I eventually learned that beta readers are not unpaid editors, but serve a key purpose in the writing process nonetheless. In fact, I’d had beta readers before and didn’t even know it!