Virtual

virtual desktop infrastructure (VDI)

Virtual desktop infrastructure (VDI) is the practice of hosting a desktop operating system within a virtual machine (VM) running on a centralized server. VDI is a variation on theclient/server computing model, sometimes referred to as server-based computing (SBC). The term was coined by VMware Inc. In the past couple of years, some large organizations have turned to VDI as an alternative to the server-based computing model used by Citrix and Microsoft Terminal Services.

virtual private server (VPS) or virtual dedicated server (VDS)

A virtual private server (VPS), also called a virtual dedicated server (VDS), is a virtual serverthat appears to the user as a dedicated server but is actually installed on a computer serving multiple Web sites. A single computer can have several VPSs, each one with its ownoperating system

(OS) that runs the hosting software for a particular user.

The hosting software for each VPS can include a Web serverprogram, a File Transfer Protocol (FTP) program, a mail server program and specialized applications for activities such as e-commerce and blogging.

The VPS alternative is often chosen by small businesses that need a customized Web site but cannot afford a dedicated server. Another useful aspect of VPS technology is the ability of a single subscriber to maintain multiple virtual servers. For example a Web site owner might use one server for the production-level Web site and the other for a "dummy site" that can be used to test planned updates, modifications or new programs.