Its really easy to update packages with YUM. YUM starts its update service as soon as you log into Linux,which shows all the available updates . You can go through the list and deselect the unnecessary packages .This is really troublesome because Fedora updates all its packages in really less time and if you do neglect it for a while you did have to deselect a number of packages . In case you want to update a specific package then do the following:
su to the root account,
In case you have not installed yum’s fastest mirror package then do so first:
root@localhost username : yum install yum-fastestmirror
Then say u want to update firefox,do the following:
root@localhost username : yum update firefox
YUM will check the updates available and ask ur permission for downloading the packages . Rest all will be done by the updater.