Understanding the RHEL, CentOS and Fedora Relationship
-
This topic comes up on a semi-regular basis and a lot of people are not familiar with how these three projects are related to one another. With the more or less recent acquisition of the CentOS project by Red Hat things have changed to a small degree and the topic is well worth visiting.
First, all three projects are part of the Red Hat family both in culture and in corporate ownership. All three distros are 100% products over Red Hat itself.
Fedora is the foundational product. Fedora is a purely free, open source project that releases frequently, has little official support, is made partially by RH staff and partially by volunteers and is tasked with delivering cutting edge packages and updates, the latest features and testing new designs. Fedora is effectively a technology preview and proving ground for packages and technologies. Fedora is well suited to desktop usage, research, testing and special cases where servers need technologies faster than they are rolled out to other products.
RHEL or Red Hat Enterprise Linux is RH's mainline enterprise product. RHEL is produced by "freezing" a specific Fedora release and designating it for "low term support". Instead of 6-12 months support like you expect from Fedora, RHEL releases get closer to a decade of support. Many Fedora releases will come out between each RHEL release. But each RHEL release is pegged to a single Fedora release - so it is possible to use Fedora to test an upcoming RHEL release early. RHEL focuses are reliability, predictability and package stability. Once you are on RHEL you know that you are getting many years of predictable support. RHEL is well suited to production servers and is the most popular server OS in the world
CentOS or Community ENTerprise OS started as a free, purely open source copy of RHEL made from the open source RHEL sources. This made CentOS a binary-identical RHEL copy (with RHEL branding removed for legal reasons.) Red Hat later bought CentOS as the distro was so popular and CentOS now has RH corporate support and is able to get the RHEL packages and testing much more quickly. CentOS is absolutely identical to RHEL but comes without the price tag (or the support.) There is obviously a transparent path from free CentOS to supported RHEL. You can started on CentOS and move to RHEL when ready without any complications or worries - they are the same thing. CentOS is extremely popular, especially in smaller businesses and on cloud computing.
It is because of this relationship that CentOS is encouraged as a learning platform for people learning Linux at home - because CentOS is completely free but is RHEL so that you can learn everything about RHEL and practices for certification and even use RHEL on your resume while not needing to use any costly or trial-limited products to do so.
-
Part of this is not correct. RHEL releases as often as not do not directly correspond to a specific Fedora release. I stumbled upon this myself when I tried to use Fedora packages in RHEL for some things (using packages for the same release of Fedora that the RHEL release was based on). Neither RHEL6 nor 7 was based on a single Fedora release:
-
@ryanov said:
Part of this is not correct. RHEL releases as often as not do not directly correspond to a specific Fedora release. I stumbled upon this myself when I tried to use Fedora packages in RHEL for some things (using packages for the same release of Fedora that the RHEL release was based on). Neither RHEL6 nor 7 was based on a single Fedora release:
True, they are starting to base it less closely now that Fedora has some additional testing that RHEL doesn't want to role in. SystemD is part of what caused this to change in RHEL 6. It's basically the same, still. Even if they based off of Fedora initially, it eventually skews as Fedora stops getting updates many, many years before RHEL does.
