[pm215]

The explanation I've read for the difference between Fedora and CentOS Stream is that RHEL branches from Fedora at major releases, but those are so far apart that there could be years and massive divergences between today's Fedora and the RHEL 8.x release that's about to come out. So CentOS Stream is the dynamically updating "thing that will become the next RHEL 8.x" and Fedora is "things that will go into RHEL 9 one day". Basically CentOS changes from "whatever was in the previous RHEL point release" to "whatever will be in the next RHEL point release".

[starfallg]

Centos moving forward is "rawhide" (aka. the testing branch) for RHEL, where packages will eventually make it to stable after some testing.

[rwmj]

This is roughly it, but it's also about making the development of RHEL itself more open. I wrote more about it here: https://news.ycombinator.com/item?id=25373050