Do you remember those times when you were living on a college campus with very noisy roommates? Or maybe they were super quiet and you enjoyed every day? The point is, it was a gamble - you never knew whom you ended up with. This is pretty much the same as having shared hosting account - you haven’t the faintest idea who is your roommate on a server. The analogy may sound funny but if someone on a shared server becomes a distributed denial of service (DDoS) attack target or get blocked for mass mailing, other accounts on the server will be affected as well. Also, if a shared account abuses server resources, the whole server will be impacted. Using a VPS is like owning a house with a 9 foot privacy fence. You won’t be bothered no matter what your neighbors are doing.
Partitioning a single server to appear as multiple servers has been increasingly common on microcomputers since the launch of VMware ESX Server in 2001. The physical server typically runs a hypervisor which is tasked with creating, releasing, and managing the resources of "guest" operating systems, or virtual machines. These guest operating systems are allocated a share of resources of the physical server, typically in a manner in which the guest is not aware of any other physical resources save for those allocated to it by the hypervisor. As a VPS runs its own copy of its operating system, customers have superuser-level access to that operating system instance, and can install almost any software that runs on the OS; however, due to the number of virtualization clients typically running on a single machine, a VPS generally has limited processor time, RAM, and disk space.[2]

VPS stands for Virtual Private Server and refers to a private, emulated dedicated hosting environment created through virtualization on a host (a computer or other device connected to other computers or devices via a network), server (called the “parent server”), or cluster of servers. It acts like a physical server but, in reality, it’s a piece of software that’s emulating dedicated hardware.
The main problem faced by users paying for VPS through bitcoin is the fact that while payments to VPS service providers are generally monthly, bitcoin generally does not support recurring payments. This is mainly due to the fact that bitcoin is a push technology i.e. a transaction which has to be initiated by the publisher rather than the client or the receiver.
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.
It comes down to basic reasons: If your business is growing and receiving more traffic, it is time to move to a more controlled setting like VPS.
VPS hosting is like you are living in an apartment complex. It means that other people are living in the same building, but you have your own secure apartment. You will get more room and restrictions will be fewer as compared to living in a dorm. It also means that if your neighbour is misbehaving, it is the problem of owner of building, not yours.
                                                    KnownHost’s Managed VPS packages operate on a platform supported by state of the art hardware, built with performance and stability in mind to provide the best VPS experience. Combined with their 24/7/365 Support team to assist you every step of the way of your web hosting journey.

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.[1]

Essentially, here’s the criteria I would use to judge things – if your site is made up of primarily static, HTML-based content, then you probably don’t need a VPS package.  However, if you have a large amount of files stored, multiple sites, dynamic content, and the possibility of major traffic from time to time, then you might consider upgrading to a VPS. It’s a powerful package that allows you to do more than you could with a shared hosting plan, but requires less investment than a dedicated server.