https://www.techradar.com/news/here-are-some-of-the-new-features-of-macos-1014-mojave

Apple revealed its latest version of its macOS operating system, macOS 10.14 Mojave, at its WWDC 2018 conference, and we’ve now got a glimpse of some of the new features that the updated Mac operating system will bring.

This is because the macOS 10.14 Mojave Developer Preview is available to download and install right now. The Developer Preview is a very early version of the software, so we wouldn’t recommend most people download it.