Oracle VirtualBox is a free and open-source virtualization platform that allows users to create virtual machines on their computers. It supports a variety of operating systems, including Windows, Linux, and macOS. Some common use cases for VirtualBox include running multiple operating systems on a single computer, testing software in different environments, and creating virtual labs for education or training purposes. VirtualBox also provides a number of advanced features such as snapshotting, which allows users to save the state of a virtual machine and return to it later, and remote display, which allows virtual machines to be accessed remotely over a network.