Every Fedora system runs a kernel. Many pieces of code come together to make this a reality.
Each release of the Fedora kernel starts with a baseline release from the upstream community. This is often called a ‘vanilla’ kernel. The upstream kernel is the standard. The goal is to have as much code upstream as possible. This makes it easier for bug fixes and API updates to happen as well as having more people review the code. In an ideal world, Fedora would be able to to take the kernel straight from kernel.org and send that out to all users.