Oracle Linux is an enterprise Linux distribution from Oracle for servers and cloud environments. According to Oracle it is the recommended Linux distribution for Oracle applications. It ships with the Unbreakable Enterprise Kernel (UEK), a kernel that stays close to the mainline Linux kernel, and a Red Hat compatible kernel is also available. Oracle Linux is built from Red Hat Enterprise Linux source code, is covered by the GPL and can be downloaded and used, with optional support. You install it on your own servers or virtual machines.
Oracle is headquartered in Austin, Texas, US, and is subject to US jurisdiction, including the CLOUD Act. Because Oracle Linux runs on your own infrastructure, your data stays on your own systems; updates and any support, however, come through Oracle. The source code is available under open-source licences, so alternatives from the same Red Hat family and European distributions exist as a fallback. Assess the dependency on a single vendor for patches and support.