If you get a hosting server of your own, it will operate independently, so it'll have its own Os and you'll be able to later install server side applications directly or script-driven websites through a hosting Cp. While keeping the Operating System updated is not always considered an absolute necessity, it can be a quite important task for a number of reasons. A newer OS version may have better support for specific hardware, so you might get better performance for the sites and web apps that you install. Your server shall also be more safe since updates often include security patches that take care of small issues which may permit unauthorized people to access your content. Last, but not least, current script versions, which are also released for both boosted security and for additional features, may need a later version of the Operating System in order to work properly and with their full capabilities.