Glossary
Notarization
Notarization is Apple's automated scan of Developer ID-signed software, producing a ticket that Gatekeeper checks before an app runs.
Notarization is an automated service run by Apple. Developers who distribute Mac software outside the Mac App Store sign it with their Developer ID certificate, enable the hardened runtime, and submit it to Apple. The service scans the submission for known malicious content and code-signing problems. If it passes, Apple issues a notarization ticket.
The ticket can be stapled to the app, installer package or disk image with the stapler tool, so Gatekeeper can verify it offline. If no ticket is stapled, Gatekeeper can look it up online. Admins can check an app's status with spctl -a -vv, which reports the source as a notarized Developer ID when the checks pass, and stapler validate confirms whether a ticket is attached.
Notarization is not an App Review. It does not judge what an app does or guarantee it is safe, and Apple can revoke tickets for software later found to be malicious. For defenders, it is a useful baseline signal that is best combined with allowlisting and endpoint monitoring.
See the Gatekeeper, XProtect and notarization guide for practical checks.