The force driving server virtualization is similar to that which led to the development of time-sharing and multiprogramming in the past. Although the resources are still shared, as under the time-sharing model, virtualization provides a higher level of security, dependent on the type of virtualization used, as the individual virtual servers are mostly isolated from each other and may run their own full-fledged operating system which can be independently rebooted as a virtual instance.
Server virtualization is possible thanks to specific software that behaves like a layer between the hardware and the server’s operating system. One such piece of software is known as Virtuozzo Containers, which sadly can’t provide actual virtualization. With this technology, certain resources are shared, root access is restricted, and the operating system can’t be modified etc. A high-quality VPS hosting provider will use XEN Hypervisor instead, which allows you to install any OS you want and gives you total autonomy over all resources including root access and the number of customization options.
If you host it in a VPS environment, your site won't share resources with neighboring sites, the way it would with shared hosting. In fact, your site lives in a partitioned server area that has its own operating system, storage, RAM, and monthly data transfer limits, so you can expect smoother, more stable site performance. The sites with which you share your server are far less likely to affect your site—or even take it down altogether—than they would be on a shared site. Knowing how VPS setups operate is just the first step, however. You still need to familiarize yourself with the essential features needed for building a rock-solid, VPS-hosted website.
As you can see, a VPS can be the perfect middle ground for many – enough flexibility and resources for those who need more access or control than on a shared server but without the cost of a dedicated server. If you need root access, you can’t get that on a shared server, but you can get it on a VPS. If your site experiences unpredictable swings memory usage, and your host provides it, then the presence of burstable memory will be attractive. And, if you’re a fan of customization, then the fact that you can customize server-level software such as PHP, MySQL, and Apache will perk your interest. In short, choosing a VPS will allow you to have many of the same characteristics of a dedicated server but in a more affordable and manageable package.