Understanding the concepts of desktop virtualization really comes down to knowing the user's work environment. For example, a person who only works at a personal computer in an office setting may require a desktop virtualization environment that is different from the salesperson who is out on the road, using a laptop for work.
According to Virtualization Review, there are five approaches to desktop virtualization.
Operating System Provisioning: Deliverable to virtual machines in the datacenter or the physical computer at the desktop. An always-on network is required.
Remote Desktop Services (RDS): Virtualization is done in the data center. Requirements are minimal on the client side. Scalability is considered a plus with RDS.
Client Hypervisors: The hypervisor is on the desktop, allowing it to run multiple virtual machines. Brian Madden writes that running multiple virtual machines is a benefit but the real value is in the potential to run one master image. "If we can figure out how to provide a single, generic master Windows image to our users no matter where they are, their apps, data, and personality can be applied on-demand once they load the shared master image."
Client-side Hosted Virtual Desktops: The virtual machine runs on top of an existing operating system. It allows the user to access the desktop any time, anywhere. The virtual desktop is managed on a hosted basis.
Application Virtualization: The application is virtualized so it runs independently on the user's operating system. The application is isolated from the underlying operating system.
Of these, the hosted services are proving most popular. But what is right for you? What desktop virtualization environment have you found that is most viable for your organization?