A virtual dedicated server (VDS) is an Internet hosting configuration that tends to offer more secured resources than shared hosting and a lower cost than true dedicated hosting. Each virtual dedicated server typically represents a separate virtual machine on a host. One host computer may hold any number of virtual machines, depending on factors such as load and the agreed upon service level. Virtual dedicated servers are often used for web hosting applications that are more resource dependent than shared hosting can handle. Other functions, such as online game servers, may be operated as well if the terms of service allow, though the performance may be diminished when compared to a true dedicated server.
Many web applications require more resources than a shared host can offer. If the high costs associated with dedicated servers or co-location are not an option, a virtual dedicated server often provides an affordable compromise. These servers are typically hosted in data centers that offer uptime guarantees and security features. Each server box can have anywhere from a handful to a few hundred virtual machines installed, each of which is guaranteed a portion of resources such as random access memory (RAM), hard drive space, and bandwidth. Inexpensive virtual dedicated servers tend to offer fewer resources due to the presence of many virtual machines on a single host, though they can still provide more stability than shared hosting.
A host that contains only a few virtual machines can sometimes offer an experience very similar to that of a dedicated server. The available RAM and bandwidth will often be quite high, and access to the central processing unit (CPU) can offer increased performance over shared options. In some cases each user will have root access on their own virtual machine, though this can vary between providers. The hardware itself is shared between the different users of each machine, and is both owned and maintained by the service provider.
In addition to traditional web hosting and more advanced Internet applications, it is often possible to use a virtual dedicated server to host an online game. Some game service providers (GSPs) operate with a virtual dedicated server infrastructure, so each client on the host is guaranteed specific resources to install and run whatever games they want. Many others sell seats or slots that represent an already installed game client. This type of hosting often offers less control over the environment, though it is typically possible to change the settings of the game or even install modifications.
