[HostSailor]

KVM, an acronym for Kernel-based Virtual Machine, is a hypervisor that is built into the Linux kernel. KVM uses hardware virtualization to achieve near-native performance, which means that the virtual machines running on KVM are almost as fast and efficient as the host operating system.

On the other hand, Xen is an open-source hypervisor that uses paravirtualization to achieve performance enhancements. Para-virtualization is a technique that enables guest operating systems to communicate directly with the hypervisor, bypassing the host operating system. This enables para-virtualized guests to be more efficient and have better performance compared to fully virtualized guests. However, para-virtualization can be more complex to implement, and not all operating systems are supported by Xen.