Oracle Linux is based on and fully compatible with Red Hat Enterprise Linux ( source code and binaries ). It has the exact same package as the same version of Red Hat Enterprise Linux and has the exact same source code as the Red Hat distribution. There are approximately 1000 packages in the distribution. Even if the source code of the two is compared byte by byte, there is no difference. The only change is to remove the trademark and copyright information. So, that’s why we can call it an Oracle Enterprise Linux.
Oracle Linux, the first version of Oracle released in early 2006, one of the Linux distributions, to better support Oracle software and hardware support. Because of the enterprise-level support plan UBL (Unbreakable Linux) provided by Oracle, many people called it an indestructible Linux.
In September 2010, Oracle Enterprise Linux released a new version of the kernel known as -Unbreakable Enterprise Kernel, optimized specifically for Oracle software and hardware, the most important is the Oracle database running on the OEL performance can be increased by more than 75%.
The Unbreakable Enterprise Kernel (UEK) is a Linux kernel built by Oracle and supported via Oracle Linux support. Its focus is performance, stability, and minimal backports by tracking the mainline source code as closely as is practical. UEK is well-tested and used to run Oracle’s Engineered Systems, Oracle Cloud Infrastructure, and large enterprise deployments for Oracle customers. (Read more about Oracle UEK)
Oracle Linux is binary compatible with Red Hat Enterprise Linux, which means that software running on Red Hat can run on Oracle. Oracle’s idea is to strengthen Linux, instead of creating one from scratch, the Oracle distribution actually has exactly the same pedigree as Red Hat. They are the same brothers. The biggest difference between Oracle Linux and Red Hat is OCFS. (Oracle Cluster File System) file system and Xen-based OracleVM virtualization technology. Oracle Linux currently supports both x86 and x86_64 platforms.
Although the Oracle Linux is free to download and use, the Oracle services and support are paid.
If you want to know the process to download the Oracle Linux and installation on VirtualBox, see this article: Download Oracle Linux to install on VirtualBox