Virtual Private Server (VPS) or Virtual Dedicated Server (VDS) are two terms that describe the same thing – a share (or slice) of a physical server. VPS’s are becoming very popular amongst web hosters and developers who’s sites requirements are greater than a shared hosting supplier can provide, but do not yet demand their own dedicated server.
With shared hosting you get some web space that you can run your site on, however, problems can arise if your site is too busy (it can affect other users with that shared hosting provider) or, if the software that you want to run (mailserver, web blog, picture gallery, bulletin …) has certain requirements that a shared hosting provider does not provide.
Web space can be had for very little money these days – $5/month will buy you some space that you can host your website on, but what if that website get’s too busy and the shared hosting provider asks you politely to “find another provider ….”? A decent dedicated server will cost you $150/month+ which, for many people, is both expensive and overkill.
This is where VPSs come in. A VPS provider buys a big server, lots of RAM, fast raid hard drives (hopefully!) and installs virtulization software on there. Normally this virtulization software is either Xen or Virtuozzo based. A decent VPS can be had for as little as $20/month for one with 256MB of memory and 10GB of hard drive space (you can go much cheaper but that may, or may not, be wise!).
So what does this mean for you, what do you actually get for your money? Basically you get your own server running your choice of linux (vps’s tend to be linux although you can get windows). You can ssh to this server, log in as root, install any software you want (almost!), delete anything you want, host as many domains as you want …. Basically, you’ve got free reign to do whatever you want. Pretty much the only software that you won’t be able to install is anything that relies on a linux kernel module that the VPS provider hasn’t loaded in the kernel.
Obviously, because you are sharing the underlying hardware with other users, it is possible for your “server” to be affected by what other people are running on the system but, if the VPS provider has configured things correctly, this should be much less of an issue than with shared hosting. Also, there are restrictions placed on things like bandwidth, swap space, inodes, etc so, if you think you may need a certain amount of a particular resource then check this out first.
VPS’s are also an excellent way to either learn or improve your linux skills. Many VPS providers give you the ability to wipe your VPS and start with a clean install of your chosen linux distribution so messing things up is not a big deal. Sometimes you can even change to a different distribution (CentOS, Fedora, Ubuntu, Debian …) from the web management interface without even contacting the provider.
VPSs are cheap and you can normally pay monthly without any long term commitment so – read some reviews, pick out a good provider and sign up and give it a go. Be warned though – if your VPS is “unmanaged” your going to have to learn to look after your VPS yourself just the same as if it were a real, physical server so you best know what you’re doing or at least be willing to learn!