If you get a server of your own, it will work independently, so it'll have its own Operating System and you'll be able to later install server side programs directly or script-driven websites through a hosting Cp. Although keeping the Operating System updated is not always considered fundamental, it can be a quite important task for a number of reasons. A newer Operating system version could have better support for specific hardware, so you may get better performance for the websites and web apps that you install. Your server shall also be more secure because updates typically include security patches that fix small problems that may enable unauthorized people to access your content. Last, but not least, newer script versions, which are also released for both improved security and for additional features, may need a later version of the Operating System in order to work effectively and with their 100 % capabilities.