This is the most obvious and popular use. Since virtual private servers provide more resources for your website (e.g. CPU, RAM, etc.) than shared hosting, you’ll find that your website feels more responsive. Plus, with full control over the virtual server, you can install and remove software at will according to your needs rather than being stuck with what the host offers.
I have multiple Linux machines at my home. Previously, when I needed SSH access to these machines I used to setup port forwarding on my router to each of these machines. It was a tedious process of enabling port forwarding and then disabling it after use. It was also difficult to remember port number forwarded for a particular machine. But now I found a cooler way to get SSH access to all my machines at home without setting up port forwarding or remembering any port numbers and most importantly, I can address my home machines with local subnet IP address, no matter wherever I connect from the internet.
The desire to run multiple operating systems was the initial motive for virtual machines, so as to allow time-sharing among several single-tasking operating systems. In some respects, a system virtual machine can be considered a generalization of the concept of virtual memory that historically preceded it. IBM's CP/CMS, the first systems to allow full virtualization, implemented time sharing by providing each user with a single-user operating system, the Conversational Monitor System (CMS). Unlike virtual memory, a system virtual machine entitled the user to write privileged instructions in their code. This approach had certain advantages, such as adding input/output devices not allowed by the standard system.
Some companies think virtual private servers and private clouds are the same thing, but these terms are not interchangeable. While the differences between virtual server hosting and private clouds might seem slim at first glance, it could mean all the difference in the world for businesses. Forbes predicts private clouds are going to end up being the next area of cloud computing focused on by businesses. Take a look at these key differences between VPS and private clouds, and for more info.
As technology evolves virtual memory for purposes of virtualization, new systems of memory overcommitment may be applied to manage memory sharing among multiple virtual machines on one computer operating system. It may be possible to share memory pages that have identical contents among multiple virtual machines that run on the same physical machine, what may result in mapping them to the same physical page by a technique termed kernel same-page merging (KSM). This is especially useful for read-only pages, such as those holding code segments, which is the case for multiple virtual machines running the same or similar software, software libraries, web servers, middleware components, etc. The guest operating systems do not need to be compliant with the host hardware, thus making it possible to run different operating systems on the same computer (e.g., Windows, Linux, or prior versions of an operating system) to support future software.
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.