XenServer Deployment Models
Xen virtualization is being deployed in a couple of different ways. A single physical XenServer can be host to multiple server applications. For instance, a Citrix server, a Web server, and an Oracle database server can all be operated on three VMs on the same physical server.
Alternatively, virtual desktops (instead of servers) can be published on the XenServer, and users can connect to virtual desktops to run their client applications. In this scenario, each user is assigned to a virtual desktop and can run his/her applications within that desktop.