CentOS / Fedora Core / RHEL 5 uses yum for software management. Yum allows you to add a new repository as a source to install binary software.
Understanding yum repository
yum repository configured using /etc/yum.conf file. Additional configuration files are also read from the directories set by the reposdir option (default is /etc/yum.repos.d and /etc/yum/repos.d.