If you get a hosting server of your own, it will operate independently, so it'll have its own Operating System and you'll be able to later install server side apps directly or script-driven sites via a hosting Cp. While keeping the Os updated isn't always considered fundamental, it can be a quite important task for a number of reasons. A more modern OS version may have better support for specific hardware, so you might get better performance for the websites and web apps that you install. Your server shall also be more secure because updates usually include security patches that fix small issues that may allow unauthorized individuals to access your content. Last, but not least, more recent script versions, which are also released for both enhanced security and for additional features, may require a later version of the Os in order to work effectively and with their full capabilities.