Handle
The @username that identifies an account on a platform — the public name people tag, mention and link to.
A handle is the @username that uniquely identifies an account — the thing people @-mention, tag and link to. It's distinct from a display name, which can be anything; the handle is the addressable, unique one.
Most platforms hand you an @name, but on Bluesky and the AT Protocol you can use a domain handle like @yourbrand.com, which doubles as lightweight verification. Keeping the same handle across platforms makes you easier to find and to put in a link in bio or a permalink.
See also