CentOS, is a Linux distribution that provides a free and open-source community-supported Linux distribution, functionally compatible with its upstream source, Red Hat Enterprise Linux (RHEL). In January 2014, CentOS announced the official joining with Red Hat.
What do you mean by “upstream” source?
Red Hat’s current Linux ecosystem model starts with the Fedora Project driving core innovation. As these technologies mature, they are slowly incorporated “downstream” into RHEL. RHEL hardens the packages of these components, adds security and other updates and integrates them into the RHEL ecosystem. From there, the RHEL source code is released to the CentOS Project community for additional developer integration to be built on the backbone of enterprise-ready code.
Thus making RHEL the upstream provider for CentOS.
What changes with CentOS Stream?
The CentOS Stream project sits between the Fedora Project and RHEL in the RHEL Development process, providing a “rolling preview” of future RHEL kernels and features. This enables developers to stay one or two steps ahead of what’s coming in RHEL, which was not previously possible with traditional CentOS releases.
When does this change take effect?
CentOS Linux 8 reached End Of Life (EOL) on December 31st, 2021.