Virtual private servers have become a popular choice for web hosting because they offer many benefits of dedicated servers at a lower cost. They also provide the added benefit of easy scalability. Since each VPS is virtualized, the configuration can be updated with a software modification rather than a hardware upgrade. Still, dedicated servers often provide better performance since all the resources of the physical machine are dedicated to a single server.
The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past. Although the resources are still shared, as under the time-sharing model, virtualization provides a higher level of security, dependent on the type of virtualization used, as the individual virtual servers are mostly isolated from each other and may run their own full-fledged operating system which can be independently rebooted as a virtual instance.