The Red Hat Enterprise Linux operating system must be a vendor-supported release.
An operating system release is considered "supported" if the vendor continues to provide security patches for the product. With an unsupported release, it will not be possible to resolve security issues discovered in the system software.
The Red Hat Enterprise Linux (RHEL) Extended Life Cycle Support Add-On (ELS) is an offering, for a fee, that provides extended support once a product is retired and has entered the Extended Life Phase. ELS allows customers to continue to receive critical impact security fixes and selected urgent priority bug fixes on a specific major version of RHEL from the end of its regular life cycle for an extended and defined period. ELS is only applicable to the last minor release of the given major release.