If you get a hosting machine 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 apps directly or script-driven sites through a hosting Control Panel. Though keeping the Operating System updated is not always considered fundamental, it can be a rather important task for several reasons. A more modern Operating system version could have better support for specific hardware, so you may get better performance for the websites and web applications you install. Your server shall also be more secure since updates usually include security patches which take care of small problems that may enable unauthorized people to access your content. Last, but not least, newer script versions, which are also released for both increased security and for additional features, may require a later version of the Os in order to work correctly and with their 100 % capabilities.