Ubuntu 19.04, code-named Disco Dingo, was released on April 18, 2019.
In an interview with eWeek, Mark Shuttleworth highlighted the use of snap packages (snaps) and the Gnome 3.32 Desktop. You can watch the interview here.
You can also read the release notes for more detail. ISOs are available at download.ubuntu.com. If you’re looking for help installing or upgrading, check out the calendar for the next Installfest in your area.
This is a recent email to the ubuntu-devel mailing list that describes not only recent changes to the do-release-upgrade process, but how it works in general. It is also posted here.
If you are unaccustomed to the command-line…first of all, you should learn the command line. But for now, the do-release-upgrade utility is used to upgrade from one Ubuntu release to another. The graphical desktop utility utilizes this as well.