There are several different conceptual models of desktop virtualization, which can broadly be divided into two categories based on whether or not the operating system instance is executed locally or remotely. It is important to note that not all forms of desktop virtualization involve the use of virtual machines (VMs).
Host-based forms of desktop virtualization require that users view and interact with their desktops over a network by using a remote display protocol. Because processing takes place in a data center, client devices can be thin clients, zero clients, smartphones, and tablets. Included in this category are:
Host-based virtual machines: Each user connects to an individual virtual machine that is hosted in a data center. The user may connect to the same VM every time, allowing personalization, (known as a persistent desktop) or be given a random VM from a pool (a non-persistent desktop). See also: virtual desktop infrastructure (VDI)
Shared hosted: Users connect to either a shared desktop or simply individual applications that run on a server. Shared hosted is also known as remote desktop services or terminal services. See also: remote desktop services and terminal services.
Client-based types of desktop virtualization require processing to occur on local hardware; the use of thin clients, zero clients, and mobile devices is not possible. These types of desktop virtualization include:
OS streaming: The operating system runs on local hardware, but boots to a remote disk image across the network. This is useful for groups of desktops that use the same disk image. OS streaming requires a constant network connection in order to function; local hardware consists of a fat-client with all of the features of a full desktop computer except for a hard drive.
Client-based virtual machines: A virtual machine runs on a fully-functional PC, with a hypervisor in place. Client-based virtual machines can be managed by regularly syncing the disk image with a server, but a constant network connection is not necessary in order for them to function.