All you have to know about RPM

The RPM Package Manager (http://www.rpm.org/) is a powerful command line driven package management system capable of installing, uninstalling, verifying, querying, and updating computer software packages.
RPM is free software, released under the GNU GPL.RPM is a core component of many Linux distributions, such as Red Hat Enterprise Linux, the Fedora Project, SUSE Linux Enterprise, openSUSE, CentOS, Mandriva Linux, and many others. It is also used on many other operating systems as well, and the RPM format is part of the Linux Standard Base.

For simply install a package do:

rpm -i package.rpm

Where "-i" is the Install parameter and "package.rpm" is the RPM you're installing. You can add more parameters to the above command,try this:

rpm -ivh package.rpm

The "-v" is for verbose and "-h" for the hashing marks. It'll print some "#" when unpacking and then installs the package. You can use "--percent" instead of "-h" if you want.

The above command is maybe the first RPM command you've learned. Upgrading to a New package can be done in 2 ways, the Freshen way and by executing:

rpm -Uvh new-package.rpm

Note that the "-U" Upgrading option simple removes the old and installed package, then install the new one. The "-Uvh" can be used to install a package too, if the package does not exist on your system the new-package.rpm will be installed.

Now imagine the situation where the new version of Samba you've just installed is not compatible with your applications, what to do? Answer: Upgrade to the old version. You can call this a "Downgrade" if you want. The command for install the Old package will be:

rpm -Uvh --oldpackage Samba-old-version.rpm

Where "--oldpackage" option says that Samba package version is older than the one installed. The command will remove the installed version and then install the Samba-old-ver.rpm.

For More hands on Refer To :

http://fedoranews.org/alex/tutorial/rpm/