A virtual private server (VPS), also called a virtual dedicated server (VDS), is a virtual server that appears to the user as a dedicated server, but that is actually installed on a computer serving multiple websites. A single computer can have several VPSs, each one with its own operating system (OS) that runs the hosting software for a particular user.

Many web sites are run on shared servers, where the number of sites hosted on a single server could run into the hundreds. Until recently, the next step up for a web site that had outgrown a shared server was to move to a dedicated server, which would host just that one site. Nowadays though, there is another choice – the virtual dedicated server. This is a server that has been partitioned into segments, each of which acts as a dedicated server. On a server of this type there would be just a few web sites, with the effect that more of the servers’ resources would be available for each web site. As an example, a server may be portioned into 5 virtual servers. This would mean that each virtual server would have the use of 20% of the servers’ resources – processor time, hard disk space and so on.

What is the advantage of this? Cost is the main advantage – the jump in price when moving from a shared server to a dedicated server is quite high. The virtual dedicated server falls into the bracket between these two choices and may be a more affordable choice. Typically a dedicated server will be about ten times the cost of a shared server, whereas a virtual dedicated server may only increase your costs by a factor of 3. Depending on the plan you choose, opting for a virtual dedicated server could save a lot of money, without too much degradation in the way that your web site performs.

There are disadvantages to this. If you have misjudged the amount of server resources that your site needs, you may still find that your web site is under-performing. This is rare though; only the most processor-intensive sites really need all of the resources that a modern server can provide.

The other disadvantage, rather more important, is that you will need to become more proficient in server administration. As is the case when moving to a dedicated server, you will be responsible for all of the software issues that may arise on the server with any of the applications you have installed. This is not a task that should be undertaken lightly – if the web site goes down due to a software issue it will be your responsibility to get it back up and running. Technical help from the web hosting company will tend to concern itself with hardware or network issues, although some plans may offer more help but at a premium.

If you feel that your web site is starting to get cramped in its current space – maybe it seems sluggish, maybe you feel that other sites on the same server are interfering with it – then you may be thinking of moving up from shared hosting. Choosing a virtual dedicated server is an option you should consider before making the large leap to a dedicated server. You may find that a virtual server is all you need, without the expense of a full dedicated server. Even if this is not the case it will save you money in the short term and the experience you gain here will make the eventual transition to a dedicated server a lot easier.