Virtual private servers or Virtual dedicated servers are a form of virtualization that split a single physical server into multiple virtual servers. The practice of partitioning a single server so that it appears as multiple servers has long been common practice in mainframe computers, but has seen a resurgence lately with the development of software and technologies such as VMware, Xen, FreeBSD Jail, User-mode Linux, Linux-VServer, FreeVPS, OpenVZ, and Virtuozzo.
In the Internet hosting service industry, virtual private servers fill a void between shared web hosting service and dedicated hosting service, and are quickly becoming the main-stay of many hosting companies.
They allow root-level access to individual clients without requiring physically dedicated servers. They are most widely used by businesses and individuals that need a customized solution that cannot be filled in a shared hosting environment.