EPEL stands for Extra Packages for Enterprise Linux and this repository contains many extra packages. What I really like about the EPEL is that packages from EPEL never conflict with standard packages.
Installing EPEL is easy on CentOS:
yum install epel-release
If that doesn’t work, please use the RPM installation option:
rpm -ivh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
rpm -ivh https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm
rpm -ivh https://dl.fedoraproject.org/pub/epel/epel-release-latest-5.noarch.rpm