With the release of Ubuntu 17.10, came loads of big changes, like GNOME replacing Unity as the default desktop, window buttons going back to the right, the ability to move the dock, and no 32-bit desktop version. There’s also a new default display server and default display manager.
Ubuntu 17.04 was a non-LTS release, which means it only has a 9-month support cycle. As of January 13, 2018, Ubuntu 17.04 has reached end of life and will no longer receive software and security updates. It’s recommended that you upgrade to 17.10.
Ubuntu 16.04 is an LTS release and will still be supported […]