rpmfusion is a merger of 3 other repos. the main objective is to provide software that for some reason or other Fedora cannot offer like mp3 codecs.
rpmfusion provides 2 main repositiories as mentioned in their Founding Principles page:
while the configuration page gives you all the possible methods of adding rpmfusion to your machine, i will concentrate here on the command line method because thats the method i used in a previous post on post system installation application installation
rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-stable.noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-stable.noarch.rpm
this is the 2nd article in a 4 part series