If you get a hosting server of your own, it will operate independently, so it'll have its own Os and you'll be able to later install server side apps directly or script-driven sites through a hosting Control Panel. Although keeping the Operating System updated isn't always considered a necessity, it can be a very important task for several reasons. A newer Operating system version might have better support for certain hardware, so you may get better performance for the internet sites and web apps you install. Your server will also be more secure because updates usually include security patches which take care of small issues which may allow 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 need a later version of the Os in order to work correctly and with their 100 % capabilities.