In macOS Sequoia, Apple has added another stumbling block to launching software that has not gone through Apple’s baseline vetting process for apps. Generally, this can be a good thing, preventing naive users from accidentally installing malware or privacy-invading software. However, for users who rely on software created by people who don’t work within the lines painted by Apple and its App Store, here’s what you need to know.
The Gatekeeper feature in macOS is something you never see called by that name. It’s designed to ensure that only certain apps can run on your Mac, even though macOS can execute any correctly constructed software for the platform. The only visible control is in System Settings > Privacy & Security > Security, where you can choose one of two options from the “Allow applications from” menu: App Store, or App Store & Known Developers. (See: How to open a Mac app from an unidentified developer).
Read more at Macworld.com