Virtual Server is Microsoft's virtual machine (VM) solution, enabling customers to run multiple operating systems concurrently on a single hardware server. Three key customer benefits:

• Legacy application migration: Migrating NT4 and Windows 2000 applications into virtual machines running on more resilient hardware and Windows Server 2003 enables simplified operations, higher service levels, and operational cost savings.
• Automated rapid deployment: Automated configuration, management and integration of portable virtual machines enable capacity on demand.
• Flexible server consolidation: Consolidating servers running line-of-business applications enables an optimized infrastructure, higher server utilization and reduced capital expenditures.

A virtual machine is essentially a computer within a computer, implemented in software. Virtual Machine technology, as implemented in Virtual Server, enables customers to run multiple server operating systems concurrently, each in its own isolated software partition, on a single physical server. An application running in a virtual machine behaves the same as an application running on a physical system?it writes information to the file system in the same manner, interacts with the network just as if it were sending packets to a physical NIC. This enables a single hardware server to run multiple operating systems concurrently, each in its own isolated partition. Virtual Server enables customers to multiply server savings.