Xen is an open-source hypervisor that allows multiple operating systems to run on a single physical machine. It creates virtual machines, enabling users to efficiently utilize hardware resources by isolating different operating systems. This technology is widely used in cloud computing and server virtualization. Originally developed at the University of Cambridge, Xen supports various operating systems, including Linux and Windows. It operates by managing the hardware and allocating resources to each virtual machine, ensuring they run independently. This flexibility makes Xen a popular choice for businesses looking to optimize their IT infrastructure.