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