If you get a hosting server of your own, it will run independently, so it will have its own Os and you can later install server side programs directly or script-driven websites through a hosting Cp. While keeping the Operating System updated isn't always considered fundamental, it can be a quite important task for a number of reasons. A more modern Operating system version might have better support for certain hardware, so you might get better performance for the sites and web applications you install. Your server shall also be more safe since updates usually include security patches which deal with small problems which may permit unauthorized people to access your content. Last, but not least, current script versions, which are also released for both increased security and for additional features, may need a later version of the Operating System in order to work properly and with their 100 % capabilities.