If you get a hosting server of your own, it will operate independently, so it'll have its own Os and you could later install server side programs directly or script-driven sites via a hosting Control Panel. Although keeping the Operating System updated isn't always considered an absolute necessity, it can be a really important task for a variety of reasons. A more modern OS version may have better support for specific hardware, so you could get better performance for the websites and web applications that you install. Your server will also be more protected because updates usually include security patches which take care of small issues that may permit 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, might require a later version of the Os in order to work effectively and with their full capabilities.