What is a Virtual Server?

• A "server" used to mean a physical computer: a machine like your desktop PC at home but built more robustly and running special software designed to let it handle incoming requests for information. As computing power grew, though, it became increasingly inefficient to do this because processor power, electricity and space were all being wasted. A "virtual server" (also known as a "virtual private server" or "VPS") exists as software within a physical server, and each physical server can run many different virtual servers. To the outside world, everything looks the same---requests go in and information comes out. Inside, though, the physical server's hardware can be used at peak efficiency, and the operator can get the most bang for their buck.
  
  

How a VPS Works

• Virtual servers fall into the general category of "virtual machines"---software that lets you emulate another operating system on your machine (if you're a Mac owner, the Parallels software that lets you run Windows at the same time as OS X is an example of a consumer-level virtual machine). On a machine with many VPS instances, a mix of virtual operating systems (depending on the client's needs and preferences) run concurrently, managed by something known as a "hypervisor." A hypervisor is software that allocates resources and transmits information to each virtual machine as its demands grow and shrink.
  
  

Advantages of Using a VPS

• For server owners, virtual private servers allow many different clients to be served simultaneously with the same machine, lowering costs and increasing efficiency. For clients, a VPS allows low-cost web hosting in a professional environment---a server company will be able to afford higher quality hardware and backup services that a client might not have access to if they were running their own server. For many purposes, like hosting a personal website to share photos with friends, a VPS is just as powerful and accessible as a real server. You might not even know that your website was being served from the same computer as a dozen others.
  
  

History of Virtual Servers

• Software engineers have partitioned powerful computers to make better use of the hardware since the 1960s, but decreasing component prices in the 1980s and 1990s saw virtualization taking a backseat to simply buying more computers. Today, however, the sheer number of servers that would be required, as well as concerns about environmentally friendly computing, have resulted in a resurgence of the use of virtual servers. The servers are used for everything from hosting websites to providing dedicated servers for people looking to play video games with their friends.