What is “Xen” and why is it so important?
Xen is an open-source hypervisor backed by the Linux Foundation. In plain English, Xen is the piece of software that carves a server up into VPSes. Think of it as a landlord or building manager. It makes sure everyone stays in their virtual space, and helps prevent one VPS from stealing resources from everyone else. Some discount VPS providers use different types of hypervisors that can allow one VPS to intrude on the resources of another -- but not us.