If you get a hosting server of your own, it will work independently, so it'll have its own Os and you could later install server side applications directly or script-driven sites through a hosting Control Panel. Even though keeping the Operating System updated isn't always considered fundamental, it can be a quite important task for a number of reasons. A newer OS version might have better support for certain hardware, so you could get better performance for the internet sites and web apps you install. Your server will also be more safe as updates usually include security patches that deal with small issues that may allow unauthorized people to access your content. Last, but not least, newer script versions, which are also released for both increased security and for additional features, may require a later version of the Operating System in order to work correctly and with their full capabilities.