A virtual private server splits a physical computer into multiple virtual computers. Each "computer" can host a separate account for different customers. This allows each user to have almost complete control over their own account. With a VPS, customers are able to make changes and manage their site without it affecting other accounts. Conversely, changes and problems with other sites hosted on the same computer do not affect your own site. Although they are on the same physical computer, the sites are hosted on separate servers. This provides a barrier of protection between separate accounts, so that problems with one site do not drag down the rest. A virtual private server is beneficial for more than just security and managing. Customization is another major draw. With a VPS, you can easily manage your own settings just the way you prefer them.
A VPS allows you to install the operating system of your choice. This is beneficial for those who prefer Linux to Windows. Most computers automatically come installed with some form of Windows, with the exception of Apple computers, which have the Macintosh operating systems. Some users, however, prefer the customizability of Linux. With a virtual private server, you have the option to install Linux on your own account. Linux is often the system of choice because it is highly stable and easily customizable. It is also more cost-effective, requiring little to no purchase. Customization is easier with Linux than any Microsoft computer, and the choices are infinitely more varied. It takes far less computer power to run-perfect for computers with little hardware to spare. The software, too, is more varied, such as text editors. This is all thanks to the open-source nature of Linux. Not only is it free for distribution, users can edit the computer system itself to function however they want.
Linux, although popular, is not a commonly used operating system, especially as a default. A shared server does not have the option to change the operating system, since all customers use the same computer and therefore the same operating system. A VPS is only one physical computer, but acts as several separate computers. This separation allows you to customize your own account, even going so far as to install your own operating system. This is a definite plus for those who prefer Linux, since it is not often found as the default operating system in most computers.
It won't. A virtual private server is specifically set up so that each account is completely separate from the rest. The only thing shared is the computer's processing capacity, known as CPU. This part of the computer does not host the operating system. Everything else, including RAM and hard drive space, is individually divided between each account, with a barrier between each so that one does not affect the other. Changes you make will not reflect on other servers, nor will the changes they make appear on yours.