Beta 1 of iOS 12.2 & MacOS Mojave 10.14.4 Released for Testing
Apple has released iOS 12.2 beta 1 and macOS Mojave 10.14.4 beta 1, along with tvOS 12.2 beta 1 and watchOS 5.2 beta 2.
These new beta builds arrive a day after the the final versions of MacOS Mojave 10.14.3 and iOS 12.1.3 were released for the Mac, and iPhone and iPad, respectively, along with other final updates to watchOS and tvOS.
Typically a developer beta build arrives first, and is soon followed by the same build being released as a public beta. Anyone can participate in the beta programs, though the Developer Beta requires an annual membership fee to be registered as an Apple Developer, whereas the public beta is free but does not include developer specific capabilities.
Presumably the first beta versions of iOS 12.2 and macOS 10.14.4 focus on bug fixes and refinements to the operating systems, perhaps even with some security enhancements, though the release notes accompanying both downloads are vague.
Mac users enrolled in the beta testing programs for macOS Mojave can find macOS 10.14.4 beta 1 available from the Software Update mechanism in System Preferences.
iPhone and iPad users participating in beta testing programs can find iOS 12.2 beta 1 available from the Settings app Software Update section.
Meanwhile, beta builds of watchOS and tvOS can be found from their respective Settings and software update mechanisms for those running beta builds on the Apple Watch or Apple TV.
The most recent final stable builds of system software for Apple devices is currently macOS Mojave 10.14.3 for Mac (and Security Update 2019-001 for High Sierra and Sierra), iOS 12.1.3 for iPhone and iPad, watchOS 5.1.3 for Apple Watch, and tvOS 12.1.2 for Apple TV.