“The memes and news site I use.”

That’s it. No infodumping, no explaining the technicalities, just tell them “just pick one, it’s basically like a username” and worry about it only if they want to learn about the underside of it.

We don’t “explain” email to people - they just pick a site, sign up, and move on.

Working in tech I learned to only explain the workings of something if they ask since most users are perfectly fine on a surface level and can intuit more than we credit them for once they know the basic gist.