VPS: Virtual Private Server
A Virtual Private Server is a virtual machine being sold as a service by Internet Hosting Service providers. As said, it is a virtual machine or an emulation of the orig9inal servers and as such has its own copy of the original OS.
It allows super-user level access to its system administration for the customers. It makes use of virtualization software to split one physical server (the original hosting by the service providers) into multiple components. VPS has become very popular among web developers with root-access needs.
VPS vs. Shared Hosting
A shared Hosting and VPS are alike in many ways except the fact that in the former one, there is a restriction for website growth as everything, i.e. resources (bandwidth, disk space, etc.) on a shared hosting environment is shared. Thus, in shared hosting, a resource of one user is affected by the use of resources for other uses.
However, VPS Hosting does not allow resource sharing as memory and bandwidth allocations are unique to each virtual environment. Hence, you get far more disk space and bandwidth and as such if your website grows it is easier to manage it and at the same time not have to be concerned about the usage of resources of others.
Also, in case of a customization need or in case of a need for technical flexibility, a VPS is always recommended over Shared Hosting. VPS allows system administration, i.e. access to install and delete software, set permissions, create accounts and more. At the same time as hardware is also shared, so the physical server maintenance is not needed.
Businesses that want many of the features of a dedicated hosting service but do not have the resources to physically realize that can turn to VPS. In terms of security, a VPS has much advanced and better security system as each hosting environment is isolated from every other VPS on the same physical server.
Reseller Hosting and VPS Hosting
Reseller Hosting is mainly applicable for Reseller businesses. A Reseller generally purchases resources, namely, bandwidth and disk space, and in return generates revenue by renting out different portions of it (resources) to different customers.
Whereas, in VPS Hosting, as mentioned above, it is simply a physical server split into multiple virtual servers and provided to customers. For example, if you already are an established business getting more traffic, such that it is difficult to manage in a shared hosting environment, then it is advisable to switch to a VPS environment as it allows much easier access for managing your resources.
The choice of a hosting service is dependent on your own needs. A reseller hosting generally means to run an online business by providing hosting services to customers. On the other hand, a VPS hosting means to run any kind of business by simply p[purchasing the hosting in order to manage your own websites.
In a reselling environment, the accounts resell to host multiple domains but are liable to the server-wide rule. In a VPS environment, however, customers are capable of running and managing their own dedicated server.
If the independent system with less resource usage than a dedicated server is what you are looking for, then you would definitely want to look into a VPS hosting environment. Then again, as I said, choice of hosting environment totally depends upon your business needs.