Centos Yum

Yum can be use to install packages in Centos. Default repository will be pointing to the nearest repository servers. You can add additional repository like this. First search for repository. Here is one of repository for RH and Centos : http://www.jasonlitka.com/yum-repository/

After adding new repository, just issue

yum list

This will update yum cache and will list all packages available to all repositories.

Then, you can just install the packages. For example :

yum install ntp

Will install ntp package.

To update all packages,

yum update

Bare in mind that to use yum command on RH, you must have a valid subscription to Redhat Network.