A VPS hosting provider relies on virtualization software, called a hypervisor, to abstract resources on a physical server and provide customers with access to an emulated server, called a virtual machine (VM). Each virtual machine runs a complete operating system, and has restricted access to a portion of the physical server's compute, memory and storage resources. Customers have access to the VM's OS, but not to the physical server.
Shared hosting: With shared hosting, your site is stored and served from the same physical machine as many other customers – possibly hundreds of them. All domains are drawing from the same CPU, RAM, and other resources. This type of hosting is the lowest-priced option. However, your site’s speed and reliability suffer from other users, and you don’t get root access.
Both single-machine and cloud-based VPSes are managed using a software program called a hypervisor. The machine that runs the hypervisor is called the host machine and the individual virtual private servers are called guest machines or guest instances. The hypervisor can start and stop the virtual machines and allocates system resources, such as CPU, memory, and disk storage to each VPS.
Our VPS Hosting plans all come with a high availability feature that essentially takes your VPS container, and empowers it with a cloud infrastructure. How does this work? We put a premium on your server's uptime, so we created an infrastructure of redundant hardware clusters that provides your partition with real-time redundancy. If for some reason there is an error on your server, there is another server in the cluster with that backup information ready to spin up. We utilize Virtuozzo, a virtualization solution built on top of OpenVZ.
A VPS runs its own copy of an operating system (OS), and customers may have superuser-level access to that operating system instance, so they can install almost any software that runs on that OS. For many purposes they are functionally equivalent to a dedicated physical server, and being software-defined, are able to be much more easily created and configured. They are priced much lower than an equivalent physical server. However, as they share the underlying physical hardware with other VPSes, performance may be lower, depending on the workload of any other executing virtual machines.