This is a short & simple guide for upgrading Fedora 22 to Fedora 23 using DNF
When you upgrade packages on RedHat based systems, the newer package replaces the older one except for install only packages e.g. kernel packages. Upgrading kernel package(s) with yum, dnf and even apt leaves 3 older versions—by default—of the kernel package(s) on the system. This can be useful in cases where you need to use to an older version.