Fedora Magazine - https://fedoramagazine.org/upgrading-fedora-27-fedora-28/
Fedora 28 was just officially released. You’ll likely want to upgrade your system to the latest version of Fedora. Fedora offers a command-line method for upgrading Fedora 27 to Fedora 28. The Fedora 28 Workstation also has a graphical upgrade method.
Upgrading Fedora 27 Workstation to Fedora 28
Soon after release time, a notification appears to tell you an upgrade is available. You can click the notification to launch the GNOME Software app. Or you can choose Software from GNOME Shell.
Choose the Updates tab in GNOME Software and you should see a window like this: