Server virtualisation is the process of encapsulating one or more complete server operating systems, and their applications, within a virtualised environment on a host server. These virtual servers are separated from the physical hardware on which they live by a virtualisation layer (sometimes referred to as the Hypervisor). This has a number of benefits in that it:
-Protects the host server from virtual server crashes and misbehaving or malicious applications.
-Allows the host server to schedule and allocate resources such as CPU cycles, memory and disk space between the virtual servers.
-Introduces the possibility of migrating a complete virtual server between physical hosts.