Virtual Private Server Explained
A Virtual Private Server (VPS), also referred to as Virtual Dedicated Server (VDS), provides the features of a dedicated server for multiple web hosting customers to share. VPS works because of the way it partitions the user accounts on the server.
In a VPS, the accounts are hosted via a process called "partitioning". A single hard drive can be divided up into many smaller drives that the operating system sees as unique, separate entities. On a VPS system, individual accounts reside completely within these separate drives. Applications are installed to individual accounts and are not shared between a single group of accounts on one big drive. This provides not only additional security, but additional control, as users can be granted "root access" to their unique drive to install and configure their own environment without effecting the configuration of any other client.
Advantages of VPS web hosting
Most hosting customers would rather have complete control of their server environments. They don't want to be hosted on a server with tens or hundreds of other users, who could easily use up all the resources or cause the server environment to be unstable. But at the same time most websites don't need a dedicated server.
The Virtual Private Server (VPS) alternative is a very attractive niche hosting solution for a fairly large chunk of web hosting clients who would like the stability of a dedicated server but on a smaller scale. With the resources setup in such a way that each person can only use what is allocated to them, your site will be more consistent because it will always have the same amount of access to the CPU, memory, and bandwidth.
Virtual Private Servers are also more secure since even as you share the memory and CPU time, you are allocated your own file system. If a website on the server is hacked, the hackers will only have access to that particular file system and would not harm the other websites.
A VPS is also much cheaper than a dedicated server.
Disadvantages of VPS web hosting
Not all providers setup or define Virtual Private Servers, also known as Virtual Dedicated Servers, the exact same way. You must make sure that your provider guarantees that their setup is robust enough to handle operations at a peak level. In the realm of VPS this can be a bit more serious, since at least the expectation is that you are operating in a more robust environment and many clients could be running more intensive applications like message boards or custom web applications. A shortfall of resources could end up causing problems for everyone hosted on such a server, therefore negating the benefits of a VPS. In a shared or dedicated environment you might be able to access more resources during peak or spike periods but since the VPS environment limits you to to your slice of the server resources, it can be a drawback.
As if the technology rich lingo of regular web hosting wasn't enough, the VPS services add a few new wrinkles. Apart from storage space and bandwidth you must also deal with CPU cycles and RAM. So you will see ads for hosting that might include *** MHz and *** MB RAM to go with the usual hosting related features. It is somewhat harder to figure out how much CPU time or RAM you might need, so seek out a hosting provider that will provide you with some benchmarks and the ability to upgrade or downgrade the VPS service if needed.