Virtualization has transformed the data center over the past decade. IT departments use virtualization to consolidate multiple server workloads onto a smaller number of more powerful servers. They use virtualization to scale existing applications by adding more virtual machines to support them, and they deploy new applications without having to purchase additional servers to do so. They achieve greater resource utilization by balancing workloads across a large pool of servers in real time—and they respond more quickly to changes in workload or server availability by moving virtual machines between physical servers. Virtualized environments support private clouds on which application engineers can now provision their own virtual servers and networks in environments that expand and contract on demand.