If you get a server of your own, it will work independently, so it'll have its own Operating System and you can later install server side applications directly or script-driven internet sites through a hosting Control Panel. Even though keeping the Operating System updated isn't always considered fundamental, it can be a quite important task for a number of reasons. A newer OS version could have better support for specific hardware, so you could get better performance for the internet sites and web applications you install. Your server will also be more secure as updates normally include security patches which deal with small issues that may allow unauthorized people to access your content. Last, but not least, current script versions, which are also released for both boosted security and for additional features, might require a later version of the Os in order to work properly and with their 100 % capabilities.