Virtualization technology is described as the platform for cloud computing. The document discusses how virtualization enables cloud computing by allowing the creation of shared resource pools and optimization of infrastructure. It also talks about how virtualization can help data centers evolve into internal clouds through the use of a Virtual Data Center Operating System (VDC-OS). Finally, it provides examples of how VDC-OS and VMware vSphere can provide services, policies, and integration of resources to enable availability, security, and scalability.