Red Hat, CentOS's Linux parent company, announced it was "shifting focus from CentOS Linux, the rebuild of Red Hat Enterprise Linux (RHEL), to CentOS Stream, which tracks just ahead of a current RHEL release." In other words, CentOS will no longer be a stable point distribution but a rolling release Linux distribution. CentOS users are ticked off.

Why? First, you need to understand what's going on. A rolling-release Linux is one that's constantly being updated. Examples of these include Arch, Manjaro, and openSUSE Tumbleweed. Here, CentOS Stream will be RHEL's upstream (development) branch. This may sound like CentOS will be RHEL's beta, but CentOS denies this. 

In the CentOS FAQ, the company states: "CentOS Stream will be getting fixes and features ahead of RHEL. Generally speaking, we expect CentOS Stream to have fewer bugs and more runtime features than RHEL until those packages make it into the RHEL release." 

Continuing on, the fixed-release model is the one most server Linux distributions have historically used. For example, besides Red Hat using it for RHEL, Canonical uses it for its mainstream Ubuntu Linux release and SUSE uses it for SUSE Linux Enterprise Server (SLES). In fixed releases, major distributions are made on a schedule, with security patches and minor updates made as needed.  

read more: https://www.zdnet.com/article/red-hat-resets-centos-linux-and-users-are-angry/