Linux

It's right. While Fedora is a community project, Red Hat does hold a special place in it as its corporate sponsor. For example, the Fedora Project Leader position must be held by a Red Hat employee.

You could argue it's the other way around - Fedora is the upstream for RHEL.

It’s the other way around: RHEL is a corporate fork of Fedora.

I was wondering about that too, but I guess it's a bit of both. From What's the difference between Fedora and Red Hat Enterprise Linux?

Think about it like this. The Fedora project is the upstream, community distro of Red Hat® Enterprise Linux. Red Hat is the project’s primary sponsor, but thousands of independent developers also contribute to the Fedora project. Each of these contributors, including Red Hat, bring their own new ideas to be tested and debated for inclusion by the larger community into Fedora Linux. This also makes Fedora an ideal place for Red Hat to put features through its own distinct set of tests and quality assurance processes, and those features eventually get incorporated into a version of Red Hat Enterprise Linux.