Microsoft has released Windows 10 Insider Preview Build 18309 (19H1) to insiders in the Fast ring. This build primarily focuses on bringing the password-less sign-in options they were testing with Windows 10 Home users to all other Windows 10 Insider versions.
If you are a Windows Insider in the Fast ring, you can update to this build 18309 by going into Settings -> Update & Security -> Windows Update and then checking for new updates.
Below we have outlined some of the major changes in this build. To see the entire release notes, you can read the blog post.