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