This document discusses server virtualization. It begins by defining server virtualization as allowing multiple operating system instances to run concurrently on one physical server by creating multiple logical server OS instances. It notes the benefits of server virtualization include consolidation, redundancy, and migration. It outlines the types of virtualization as full virtualization using a hypervisor, paravirtualization where guests are aware of each other, and OS-level virtualization without a hypervisor. Applications of virtualization include virtual private servers and parallel OS environments. Limitations include unsuitability for applications requiring high processing power and disk space. The future of virtualization includes more integration.