Red Hat used to sell support and still give away their OS (which was called Red Hat Linux) with entitlements so you could get updates off of their site. Because their OS was free to upgrade they had a rather short life-cycle (4 years if I remember correctly). but you could update to the next OS for free so it was no huge deal.
In 2003(?) Redhat decided to change its business model and cease to provide entitlements for free (They also stopped providing the iso’s or binary packages for their OS for free). To avoid confusion the took the current RedHat Release (Red Hat 9) and renamed it RedHat Enterprise Linux (Version 2.1). Red Hat Enterprise Linux (RHEL) was put on a slower development cycle, 18-24 months per release and given a longer support cycle of 7 years.
At the same time RedHat started the Fedora Project which would continue providing RedHat Linux for free with update support to the Linux community. To avoid confusion they copied RedHat 9 and started calling it Fedora Core. While Redhat Fronted everything needed to start the organization they did not run it (but do provide a huge amount of directional guidance).
The Fedora Project Took over where RedHat left off it is a distribution which is bleeding edge and has a short turn around for updates. The Fedora project also continued providing support for Red Hat Linux 7/8/9 for some years after those names were discontinued.
People using RedHat 7/8/9 had several choices when RedHat made the move:
(1) Continue using RedHat Linux with updates from the Fedora Project (Which many did for a good long time)
(2) Pony up the money and start using RHEL (Which is the direction I took my shop into)
(3) Switch to a different Distro or OS
The move by Red Hat horked off many people (myself included) but it has ensured the health of Red Hat the company and in the end its always nice to have a vendor who will be around awhile. It was a great business decision by Redhat and they have went out of their way to make it up to their customers.
It's already clear, crystal in fact. The Linux pimps like to try and complain about the manner in which Microsoft supports their operating systems that were released 7-8 years ago, when the fact is no Linux vendor supports anything at all from that far back. When exposed on their hypocrisy they then resort to further absurdities such as trying to claim providing security patches isn't actually providing support. Most everyone is used to their BS by now though, and still runs these old Windows operating systems despite the constant linux lie campaign against them.