V.P.S. stands for (Virtual Private Server), from Wikipedia we have:
Virtual private server (VPS) is a marketing term used by Internet hosting services to refer to a virtual machine for use exclusively by an individual customer of the service. The term is used to emphasize that the virtual machine, although running in software on the same physical computer as other customers' virtual machines, is functionally equivalent to a separate physical computer, is dedicated to the individual customer's needs, has the privacy of a separate physical computer, and can be configured to run as a server computer (i.e. to run server software). The term Virtual Dedicated Server or VDS is used less often for the same concept.
So, they are virtual machines running over a real one using a virtualization software like XEN, VMWARE, QEMU, VirtualBox and others.
When to use a VPS
The question is: Should I get a VPS?
You may need a VPS only if you want to have some how assured resources, I mean you need to have some specfic amount or RAM or CPU power, being the last one a little more difficult to have in a SLA agreement.
Usually what you have is a "big" server running a virtualization software and above that let's say 10 Virtual Machines, the RAM can be specified for each VPS, but the CPU power (cycles) are not assured, and will be shared between the other 9 customers, while the server is not busy you may have all horse power for you, but you may expect little than 1/10 of the CPU power at any given moment.
That will sure depend on the virtualization software, and how well the main server is configured.
You also want to go to a VPS solution when you need full root access, some applications may need full root access, and then you have no other option than going to a VPS, or getting your own server, but that is too expensive.
But, not everything is good news, if you go to a VPS solution be prepared for:
- Be in charge of the O.S. upgrades
- The full server security
And other things, so at the end of the day you get more power but a lot more job.
There are a lot of providers offering VPS hosting, just do a google search and you will find a lot to choose.
Well, before getting your VPS be sure to consider you really need this:
- Full root access
- Your own IP
- Assured amount of RAM
- Your own MySQL, Apache or other Server
If you do not need some of all these things, you may want to consider a shared hosting, and later go to a VPS, also you should know that you should have experience in the operating system that your VPS will run.