As a reminder, Fedora 22 has been released last week, bringing better notifications, refined themes, application improvements and DNF as the default package manager, among other changes. For information about Fedora 22, see this article.

Also worth mentioning, Fedora 20 will reach End of Life (EOL) on the 23rd of June, 2015 and all the users should upgrade to the latest Fedora system, in order to benefit from both the latest changes and security fixes.
In this article I will show you how to easily upgrade your Fedora system (Fedora 20 or Fedora 21) to Fedora 22, via the FedUp tool.
The first thing we have to do is to install update the repository index and install FedUp:
$ sudo yum update
$ sudo yum install fedup
Notice: make sure that you have a reliable internet connection and if you are using a laptop, plug it in the power source, because the process may take some time and a sudden system turnoff may brick your current system.
Now that FedUp is installed, let’s start the upgrade process. The below command performs an over-the-network installation, grabbing all the needed packages from the internet:
$ sudo fedup --network 22
If the FedUp tool reaches step 3 without errors, reboot your system:
$ sudo reboot
Next, choose the System upgrade (fedup) option from the GRUB menu
Bonus tip. The easiest way to install multimedia codecs, new fonts, Adobe Flash Player, Oracle Java, Atom, Brackets, Oracle Java plugins, Android Studio and other software, is to use Fedy. To install Fedy, paste the below oneliner in your terminal and hit enter:
$ sudo dnf install curl
$ su -c "curl https://satya164.github.io/fedy/fedy-installer -o fedy-installer && chmod +x fedy-installer && ./fedy-installer"
After the software gets installed, it will automatically open, permitting the users to install software on their Fedora 22 system.