If you get a hosting server of your own, it will work independently, so it will have its own Operating System and you could later install server side apps directly or script-driven sites via a hosting Control Panel. Although keeping the Operating System updated is not always considered an absolute necessity, it can be a very 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 which you install. Your server will also be more protected because updates often include security patches which fix small problems 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, might require a later version of the Os in order to work properly and with their full capabilities.