Anybody interested in your writing might want to know more about you (especially if they'd like to hire you). That's why you can add an extended bio to your Authory page here.
Here is how the bio works:
The first paragraph of your bio will be shown on your Authory page by default (max. 140 characters). Everything that follows, the extended bio, will be visible after clicking "Read more":
We've tried to make things as easy as possible for you. That's why when editing your bio, you'll see what's going to be visible by default and what will be visible after clicking the link (text with grey background):