Background information: Packages and package managers
Fedora Linux uses the concept of RPM packages for installing applications. An RPM package is a single file which can be used to install or upgrade a program on your system. RPM Packages contain all the files, metadata and other information the system needs to know about the program you want to install or upgrade. Because packages installed on your Fedora system are managed by the RPM package manager, packages are easy very to install, uninstall, upgrade or even verify. For example, you can ask the system to tell you which package installed any given file.
PackageKit is a relatively new utility which allows you to graphically install, remove, or update packages on your system. To start PackageKit, select System > Administration > Add/Remove Software from the menu.
To install packages, simply use the search bar to filter through all of the available packages. Alternatively, you can select a category to browse through the list of packages relating to that topic.
Click on any package name in the list to see more information about it. If you would like to install an application, tick the checkbox next to its name and click on the Apply button to install all of the packages selected this way.
Removing packages is, in effect, the exact opposite of installing packages. To uninstall a package, just locate for the package you wish to remove using search or the category lists and instead of ticking the checkbox next to the package name, untick it. Clicking Apply will remove the packages that were unselected this way, along with any updates you may have applied to them.
PackageKit automatically checks for updates periodically and if any updates to packages installed on your system are available, a small star-like icon will appear next to the system clock. Clicking this icon and selecting Show Updates from the menu that appears will allow you to select which package updates you would like to download and install.