Guests

Guests are people who used your site without signing in. They have no account and no name. An anonymous visitor is recognised by three weak signals: a first-party cookie, a scrambled form of their address, and a scrambled browser fingerprint. None of them is stored in a form that can be read back.

Blocking

A block uses all three signals at once. Blocking only the strongest one would be the same as blocking nobody, because a visitor can simply clear their cookies.

You can lift a block from the same page.