One of the first technologies worth mentioning is called Gatekeeper. It gives users direct control over what apps are allowed to be installed. Thus, it is possible to enforce the policy by allowing only apps from the App Store to be used. All apps aiming to appear on the App Store should be signed with a certificate issued by Apple and reviewed by its engineers to ensure they are generally free of bugs, up to date, secure, and don't compromise user experience in any way.
Default Gatekeeper settings also allow applications from outside the App Store that still have a valid developer ID signature, which means the app is signed using a certificate issued by Apple. In addition, it is possible to submit an app to Apple for notarizing. In this case, the files are checked by automatic malware scanning and signature checking; as a result, the ticket is issued to be distributed with the app and is available online. So, when the user executes such an app, they get a notification...
