Anonymous sharing link
An anonymous sharing link grants access to a file or folder without requiring the person using the link to authenticate, subject to the link's permissions and service settings.
With an anonymous link, possession of the link is enough to use the access it grants. Sending it to one supplier does not restrict it to that supplier. Someone can forward the same link to another person.
Microsoft calls these Anyone links in SharePoint and OneDrive. Its Specific people links work differently: they require the recipient to authenticate as an intended user. An organization can restrict whether Anyone links are available and apply controls such as expiration and permitted actions. Those are Microsoft examples; other services have their own settings.
Convenience changes who can get in
Switching a named-recipient share to an anonymous link can remove the identity check that was blocking an unfamiliar person. That is why “the link does not work, please change it to Anyone” deserves a closer look. Confirm who needs access and why the existing method failed. The Anyone-link request article follows that decision.
Do not assume an anonymous visit identifies its reader. Without authentication, the service cannot establish that the visitor was the person the sender intended.
Deleting the link removes that access path. It does not recover downloaded copies or remove separate permissions someone already holds. External guest approval covers the alternative of granting access to an identified guest, including the need to review the grant itself.