If you get a hosting machine of your own, it will operate independently, so it'll have its own Operating System and you could later install server side apps directly or script-driven websites through a hosting Control Panel. Although keeping the Operating System updated is not always considered fundamental, it can be a quite important task for a number of reasons. A newer Operating system version could have better support for certain hardware, so you might get better performance for the sites and web apps which you install. Your server will also be more secure since updates normally include security patches which take care of small issues which may enable unauthorized people to access your content. Last, but not least, more modern script versions, which are also released for both increased security and for additional features, may require a later version of the Operating System in order to work correctly and with their full capabilities.