The new beta versi of macOS High Sierra 10.13.5 can be downloaded via the Apple Developer Center or through the software update mechanism of the Mac App Store with the appropriate profile installed.
macOS High Sierra 10.13.5 introduces support for Messages iCloud, a feature that was previously present in the MacOS High Sierra 10.13.4 beta before being pulled before the release of the update . Messages iCloud are also available in iOS 11.4.
Messages iCloud is designed to store your iMessages in iCloud for better synchrizati. At the present time, incoming iMessages are sent to all devices which you are cnected to your Apple ID, but this is not true cloud-based synchrizati because your old es messages are not displayed new devices. your devices, both features enabled via Messages iCloud.
Messages iCloud also allow you to store your old iMessages and attachments in iCloud rather than your iPhone, iPad or Mac, which saves valuable storage space.
Update probably includes bug fixes and performance improvements for issues not covered in macOS High Sierra 10.13.4, but Apple does not provide detailed release notes for macOS High Sierra updates , we do not know exactly included until the new software is …