Red Hat Enterprise Linux 5/6 is an old, yet still supported branch of the award winning and highly acclaimed RHEL (Red Hat Enterprise Linux) operating system, a distribution of Linux developed and published by the powerful Red Hat company.
The latest version, Red Hat Enterprise Linux 6.8, provides both updated installation media for Red Hat. Distribution Release: Red Hat Enterprise Linux 6.8: Rate this project: Red Hat has announced the availability of an updated version of Red Hat Enterprise Linux 6. A user can download and use this enterprise-level operating system free of cost.
CentOS is a Linux operating system, which is a 100% compatible rebuild of the Red Hat Enterprise Linux.