If you get a hosting server of your own, it will run independently, so it'll have its own Operating System and you'll be able to later install server side programs directly or script-driven websites through a hosting Control Panel. Even though keeping the Operating System updated is not always considered an absolute necessity, it can be a quite important task for a variety of reasons. A newer OS version could have better support for certain hardware, so you may get better performance for the internet sites and web applications that you install. Your server will also be more safe because updates often include security patches which fix small issues which may enable 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, might require a later version of the Os in order to work properly and with their full capabilities.