The Red Hat Enterprise Linux Life Cycle is designed to reduce the level of change within each major release over time increasing predictability and decreasing maintenance costs. Every major version of Red Hat Enterprise Linux is maintained and supported independently during the life cycle.
The Life Cycle identifies the various levels of maintenance for each major release of Red Hat Enterprise Linux over a total period of seven years from the initial release date, which is often referred to as the general availability date. The seven year life cycle for a major release of Red Hat Enterprise Linux is divided into three phases.
Production 1 Life Cycle Phase
During Production 1, at a minimum, qualified security errata of important and critical impact, as well as, urgent priority bug-fix errata may be released independent of minor releases.
If available, refreshed hardware enablement and select enhanced software functionality may be provided at the discretion of Red Hat, generally via minor releases. Minor releases will also include all available and qualified errata.
Production 2 Life Cycle Phase
During the Production 2 life cycle phase, at a minimum, qualified security errata of important or critical impact, as well as, urgent priority bug-fix errata may be released independent of minor releases.
If available, refreshed hardware enablement that does not require substantial software changes may be provided at the discretion of Red Hat via minor releases. New software functionality is not available during this phase. All available and qualified errata will be provided via the minor releases. The focus for minor releases during this life cycle phase lies on resolving defects with a minimum priority of high.
Production 3 Life Cycle Phase
During Production 3, at a minimum, qualified security errata of important or critical impact and selected mission critical bug fixes may be released independent of minor releases.
No new functionality, new hardware enablement or or updated installation images are planned for release in Production 3 life cycle phase. There are no minor releases planned during this phase.
For detailed information, please refer to this link at official website Redhat.com.