Oracle Linux ships with two kernels... the Red Hat kernel and the Oracle Linux kernel (optimised for use with Oracle products).
Support for Oracle Linux is FREE when it is running any supported Oracle product.
Support for Oracle/Red Hat Linux running non Oracle software (irrespective of kernel) is cheaper through Oracle than it is through Red Hat (it used to be 50% of the cost, but not sure if that is still true)
Oracle Linux Premier Support includes proprietary code called KSplice which allows Kernel and user space patching without downtime (for Red Hat and Oracle Linux)
Oracle Linux is binary compatible with RHEL
The days of CentOS as a free, stable, production ready version of Red Hat Enterprise Linux are over. The End Of Life (EOL) date for CentOS 8 was 31-Dec-2021, EOL for CentOS 7 runs until 30-Jun-2024 in order to give customers time to migrate to something else. CentOS Stream 9 fundamentally changes CentOS into what is, ostensibly, a rolling Beta test distribution for RHEL (if you consider Fedora as Alpha test). It is broadly equivalent to the RHEL nightly builds. The bottom line is, you probably should not be using CentOS Stream for production.Â